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Computer Standards & Interfaces 97 (2026) 104106
Contents lists available at ScienceDirect
Computer Standards & Interfaces
journal homepage: www.elsevier.com/locate/csi
A novel hybrid WOAGWO algorithm for multi-objective optimization of
energy efficiency and reliability in heterogeneous computing
Karishma , Harendra Kumar
Department of Mathematics and Statistics, Gurukula Kangri (Deemed to be University) Haridwar, Uttarakhand 249404, India
ARTICLE INFO ABSTRACT
Keywords: Heterogeneous computing systems are widely adopted for their capacity to optimize performance and energy
Energy-efficient scheduling efficiency across diverse computational environments. However, most existing task scheduling techniques
Heterogeneous computing address either energy reduction or reliability enhancement, rarely achieving both simultaneously. This study
Hybrid WOAGWO
proposes a novel hybrid whale optimization algorithmgrey wolf optimizer (WOAGWO) integrated with
Metaheuristics
dynamic voltage and frequency scaling (DVFS) and an insert-reversed block operation to overcome this
Reliability optimization
Sensitivity analysis
dual challenge. The proposed Hybrid WOAGWO (HWWO) framework enhances task prioritization using the
dynamic variant rank heterogeneous earliest-finish-time (DVR-HEFT) approach to ensure efficient processor al-
location and reduced computation time. The algorithms performance was evaluated on real-world constrained
optimization problems from CEC 2020, as well as Fast Fourier Transform (FFT) and Gaussian Elimination (GE)
applications. Experimental results demonstrate that HWWO achieves substantial gains in both energy efficiency
and reliability, reducing total energy consumption by 55% (from 170.52 to 75.67 units) while increasing system
reliability from 0.8804 to 0.9785 compared to state-of-the-art methods such as SASS, EnMODE, sCMAgES, and
COLSHADE. The experimental results, implemented on varying tasks and processor counts, further demonstrate
that the proposed algorithmic approach outperforms existing state-of-the-art and metaheuristic algorithms by
delivering superior energy efficiency, maximizing reliability, minimizing computation time, reducing schedule
length ratio (SLR), optimizing the communication-to-computation ratio (CCR), enhancing resource utilization,
and minimizing sensitivity analysis. These findings confirm that the proposed model effectively bridges the
existing research gap by providing a robust, energy-aware, and reliability-optimized scheduling framework for
heterogeneous computing environments.
1. Introduction as multiprocessor task scheduling is an NP-hard optimization problem,
delivering a valid solution within a predefined deadline remains a
1.1. Motivation significant challenge for real-time applications in heterogeneous sys-
tems [4]. Alternatively, the delicate balance between performance
In recent years, the exponential growth in data volume and com- and power consumption stands as a pivotal factor in the design of
putational demands has propelled the development of heterogeneous multiprocessor systems [5]. To attain optimal performance, it is im-
computing systems. Numerous computing resources are required for perative to implement efficient scheduling of applications across the
various heterogeneous computing models, such as utility computing, diverse resources within heterogeneous computing systems, comple-
peer-to-peer, and grid computing. These resources can be allocated mented by efficient runtime support mechanisms [6]. In multiprocessor
through the network in order to fulfill the needs of carrying out systems, scheduling of tasks involves arranging the sequence of tasks
high performing tasks [1]. Resource scheduling is a fundamental chal- and facilitating their execution across selected processors to achieve
lenge in heterogeneous computing, especially as the number of tasks a predetermined goal, such as meeting deadlines, minimizing over-
and resources increases. Inefficient task allocation can lead to pro- all execution time (makespan), conserving energy, enhancing system
reliability, among other objectives [7].
cessor overutilization or underutilization, complicating the scheduling
Efficiently managing energy consumption is pivotal in the design
process [2]. Heterogeneous distributed computing has proven highly
of heterogeneous distributed systems. This is essential as the dissi-
effective in handling diverse and complex end-user tasks, driven by ad-
pation of energy directly influences not only the development and
vancements in network technologies and infrastructure [2,3]. However,
Corresponding author.
E-mail addresses: maths.karishma97@gmail.com (Karishma), balyan.kumar@gmail.com (H. Kumar).
https://doi.org/10.1016/j.csi.2025.104106
Received 14 February 2025; Received in revised form 14 November 2025; Accepted 28 November 2025
Available online 7 December 2025
0920-5489/© 2025 Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
Karishma and H. Kumar Computer Standards & Interfaces 97 (2026) 104106
operation of the system but also profoundly impacts the individuals HWWO leverages this approach to achieve superior scheduling perfor-
within the living environment [8]. The rise in energy consumption mance by harnessing the complementary strengths of WOA and GWO
has emerged as a significant concern, which has a direct impact on while mitigating their individual drawbacks.
the costs associated with computing services. This consumption typ- The WOA demonstrates superior exploration capabilities through
ically comprises dynamic energy resulting from switching activities its advanced updating mechanism, employing a randomized search
and static energy arising from leakage currents [9]. Recognizing the approach to dynamically shift positions and navigate towards optimal
importance of energy conservation, researchers have explored and solutions. As highlighted by [30], WOA strikes a good balance between
developed several techniques to address this issue. These include mem- exploration and exploitation, exhibiting notable convergence speed in
solving optimization problems. However, despite its effectiveness rela-
ory optimization, DVFS, and resource hibernation. DVFS, also known
tive to traditional algorithms, WOA can struggle to escape local optima
as dynamic speed scaling (DSS), dynamic power scaling (DPS), and
due to its encircling mechanism [31] and may fail to effectively refine
dynamic frequency scaling (DFS), is particularly noteworthy for its
the best solutions. Conversely, GWO excels in exploitation through
potential to save energy [10,11]. This technique facilitates energy-
strong local search capabilities but suffers from limited diversity in
efficient scheduling by dynamically adjusting the supply voltage and the early stages, which can hinder global search. To address these
frequency of a processor while tasks are running, thereby optimizing limitations, we have proposed a hybrid approach that augments WOA
energy usage [1214]. The implementation of dynamic voltage scaling with mutation operators and integrates it with GWO to enhance overall
for energy-efficient optimization presents a noteworthy advancement. scheduling performance. Recognizing that excessive mutation can dis-
Nevertheless, it is essential to acknowledge a potential drawback: an rupt previously discovered good solutions and impede convergence, we
elevated risk of transient failures in processors, which could undermine have incorporated an insert-reversed block operation after mutation to
the reliability of systems [9,15]. Reliability pertains to the probability preserve solution quality and improve the algorithms efficiency.
that a schedule will successfully complete its execution within the This study endeavors to attain an optimized energy-efficient
defined parameters [16,17]. Higher frequencies typically correspond scheduling algorithm with a maximal systems reliability, thus minimiz-
to both high energy consumption and enhanced reliability, whereas ing the aggregate energy consumption of precedence-constrained tasks
lower frequencies are associated with decreased energy consumption in parallel applications executed on heterogeneous computing systems.
and reduced reliability [18]. When an application meets its designated The primary contributions of this research are succinctly outlined as
reliability objective referred to as a reliability goal, requirement, follows:
assurance, or constraint in various studies it is deemed reliable in • This article proposes innovative hybrid algorithmic approaches
accordance with functional safety standards. These standards include that combine the WOA and GWO to tackle the intricate problems
DO-178B for avionics systems, ISO 26262 for automotive systems, and related to energy-efficient tasks scheduling.
IEC 61508 for a broad spectrum of industrial software systems [8,19]. • This study meticulously designs energy-efficient scheduling algo-
rithms that leverage the hybrid WOAGWO to effectively opti-
1.2. Our contributions mize two key objectives; energy consumption and the reliabil-
ity of the system. The algorithms ensure compliance with the
Task scheduling, an NP-hard problem, increases the complexity of deadline constraints of parallel applications.
voltage adjustment choices in heterogeneous computing systems [20, • The proposed algorithm assigns tasks to suitable processors by
21]. Balancing energy efficiency and reliability presents a major chal- synergistically integrating the HWWO technique with DVFS tech-
lenge, as prioritizing one often complicates optimizing the other [18]. nology. Here, the proposed algorithm applies the mutation opera-
Scheduling algorithms are broadly classified into heuristics and meta- tor in conjunction with the insert-reversed block operation as part
heuristics. Heuristic methods, which use greedy strategies for optimal of the HWWO technique and helps to mitigate the static energy
selection [22], are computationally efficient but often fail to perform consumption. Additionally, the DVFS technique has been utilized
to mitigate the dynamic energy consumption.
well in complex or large-scale scheduling problems [21,23]. In contrast,
• Comprehensive experimental evaluations are carried out by com-
metaheuristic algorithms, inspired by natural processes, offer more reli-
paring the proposed HWWO algorithms performance against sev-
able results and greater flexibility [24]. Metaheuristics are popular due
eral well-known algorithms, including the FFT, GE, and four
to their simplicity, adaptability, independence from derivative-based
benchmark algorithms from the CEC2020 Competition — SASS,
methods, and ability to avoid local optima. Authors [25] developed
EnMODE, sCMAgES, and COLSHADE. Furthermore, the algorithm
an optimized gravitational search algorithm (GSA) to enhance feature- is subjected to testing on a set of unimodal benchmark test
level fusion in multimodal biometric systems. Their work demonstrated functions.
how metaheuristic optimization can effectively improve system perfor- • The experimental results demonstrate that the proposed algo-
mance through better parameter tuning and search-space exploration. rithmic approach outperforms existing state-of-the-art and meta-
Authors [26] developed a hybrid white shark optimizersupport vector heuristic algorithms by delivering superior energy efficiency,
machine (WSOSVM) model for gender classification from video data, maximizing reliability, minimizing computation time for tasks
where the white shark optimizer was used to fine-tune SVM param- assignment, minimizing sensitivity analysis and SLR, CCR, and
eters, leading to improved accuracy and faster processing compared enhancing resource utilization. These promising results hold true
to traditional SVM methods. In [27] authors developed two novel across various scale conditions and deadline constraints.
task scheduling models based on the metaheuristic GWO technique to • Conduct an evaluation of the proposed techniques computational
optimize energy consumption while minimizing computational time for complexity during execution and employ the Wilcoxon-signed
parallel applications. In this article, a novel hybridization (HWWO) of rank statistical test to validate its performance.
the WOA [28] and GWO [29] is employed to tackle the task scheduling
The structure of the article is outlined as follows. Section 2 offers
problem. Hybrid algorithms are designed to integrate the features of an extensive review of relevant literature and related works. Detailed
various metaheuristic approaches, exploiting their synergy to address explanations of the WOA and GWO techniques are covered in Section 3.
complex optimization challenges. This fusion not only enhances the In Section 4, pertinent models and problem formulations are explored,
efficiency and flexibility of the algorithms but also augments their along with essential notations used throughout the study. Section 5 pro-
overall performance, often surpassing that of traditional metaheuristic vides a thorough description of the proposed model. The development
algorithms. Furthermore, a wide range of such hybrid algorithms has of simulation experiments to evaluate the proposed model is detailed
been developed, driving the evolution of new-generation metaheuristics in Section 6. Finally, Section 7 elaborates on the studys conclusion,
that effectively balance exploration and exploitation. The proposed discussing limitations and directions for future research.
2
Karishma and H. Kumar Computer Standards & Interfaces 97 (2026) 104106
2. Literature review and physical systems. Among these, swarm intelligence (SI) methods
form a prominent category, drawing on the collective behavior of
The substantial energy consumption associated with computing living organisms. These algorithms utilize population-based, stochastic,
systems poses a significant impediment to their rapid advancement. and iterative strategies. Numerous real-world challenges, including
Therefore, minimizing energy usage while ensuring system reliability drone deployment, image processing, wireless sensor network localiza-
has become a pressing concern for fostering sustainable computing tion, machine learning optimization, and others, have found effective
methodologies. Researchers from multiple fields have devoted substan- solutions by employing SI techniques [2,50]. Beyond their diverse
tial efforts to investigating the intricate challenges associated with task applications, SI algorithms have undergone continuous enhancements
scheduling techniques that strike a balance between minimizing energy through modifications, hybridizations with other techniques [51], and
consumption and maximizing system reliability. parallel computing implementations [52]. These efforts aim to further
In the realm of sustainable computing systems, DVFS technique has optimize their performance and obtain superior solutions across di-
emerged as a prominent and widely employed method for efficiently verse problem domains. SI algorithms are inspired by the collaborative
curtailing energy consumption [32]. A study by [33] addressed energy- behaviors observed in various animal and insect communities, where
aware task assignment for deadline-constrained workflow applications entities interact and respond to their environment collectively. This
in heterogeneous computing environments. Earlier, [34] explored the- includes animal herds, ant colonies, fish schools, bacterial aggregations,
oretical models for DVFS and proposed an energy-aware schedul- and bird flocks etc. These algorithms exhibit notable advantages in-
ing strategy for single-processor platforms. Advanced algorithms like cluding adaptability, user-friendliness, and reliability [53]. Some of the
enhanced energy-efficient scheduling (EES) [35] and DVFS-enabled recently developed SI algorithms are artificial bee colony (ABC) [54],
energy-efficient workflow task scheduling (DEWTS) [36] were later ant colony optimization (ACO) [55], cuckoo optimization algorithm
developed to reduce energy consumption in parallel applications. EES (COA) [56], particle swarm optimization (PSO) [57], horse herd op-
uses DVFS to slack non-critical tasks while meeting time constraints, timization algorithm [58], krill herd (KH) [59], crow search algorithm
while DEWTS enhances energy efficiency by selectively turning off (CSA) [60], GWO [29], sailfish optimizer (SFO) [61], and WOA [28]
processors to minimize static energy consumption. In [37], authors etc.
proposed the downward energy consumption minimization (DECM) This study implements the WOA algorithm to address energy-
algorithm that innovatively transfers application deadlines to task-level efficient and reliable task scheduling in heterogeneous computing
deadlines using deadline-slack and task level concepts, enabling low- environments. The approach enhances WOA by hybridizing it with
complexity energy minimization. Authors [38] proposed a two-stage GWO, leveraging the strengths of both techniques. WOA, introduced
solution to enhance the reliability of automotive applications while by Mirjalili and Lewis in 2016 [28], is a notable method in swarm
satisfying energy and response time constraints. First, it solved response intelligence optimization. Inspired by the remarkable hunting strategies
time reduction under energy constraint (RREC) via average energy employed by humpback whales in the vast ocean, this algorithm
pre-allocation. While, the second stage enhanced reliability within the demonstrated competitive or superior performance compared to sev-
remaining energytime budgets from the RREC stage. Addressing the eral existing optimization methods [28]. Similar to WOA, GWO is
challenge of energy-efficient tasks scheduling in cloud environments, a nature-inspired metaheuristic optimization algorithm based on the
the authors of [39] proposed an algorithm based on DVFS that pri- social behavior and hunting strategies of grey wolves [29]. It is widely
oritizes tasks by deadline, categorizes physical machines, and assigns used for solving complex optimization problems. WOA, recognized for
tasks to nearby machines in the same priority class. Researchers in- its unique approach, has been effectively applied to scheduling tasks
troduced the energy makespan multi-objective optimization algorithm in cloud computing, aiming to enhance system performance within
for energy-efficient, low-latency workflow scheduling across fogcloud constrained computing capacities [62]. The researchers proposed an
resources [40]. The research work of [41,42] aimed to devise an innovative scheduling approach based on WOA that combined multi-
approach that could reduce the overall execution time for parallel objective optimization with trust awareness. It mapped tasks to virtual
applications running on high-performance distributed computing en- resources based on priorities, evaluated trust via SLA parameters,
vironment, while concurrently enforcing adherence to predetermined and enforced deadline constraints for task execution on VMs [63].
energy consumption thresholds. The study tackled the challenge of scheduling tasks on heterogeneous
Reliability-aware design algorithms aimed at ensuring reliability multiprocessor systems equipped with DVFS capabilities. The objective
typically try to reduce certain objectives while also satisfying relia- was to optimize energy consumption while adhering to constraints
bility requirements. Improving the reliability of parallel applications related to makespan and system reliability. To achieve this, [64]
frequently results in longer schedules or higher energy usage. Opti- proposed an enhanced variant of the WOA, incorporating opposition-
mizing both schedule length (or energy consumption) and reliability based learning and an individual selection strategy. In the article [65],
concurrently poses a classic bi-criteria optimization problem requiring the authors introduced an improved whale algorithm (IWA) to opti-
the identification of pareto-optimal solutions [43,44]. The researchers mize tasks allocation in multiprocessing systems (MPS), minimizing
in [45] introduced an approach to reliably assign and schedule tasks energy consumption and makespan. They utilized DVFS and addressed
on heterogeneous multiprocessor systems, tackling the complexities task schedulings NP-hard nature. The article [66] addressed power
and potential failures associated with critical applications. Researchers consumption in cloud infrastructure, underscoring the necessity for
in [46,47] tackled the intricate problem of workflow scheduling on energy-efficient algorithms and load balancing techniques. The authors
heterogeneous computing systems, aiming to achieve high reliability employed various optimization algorithms, such as PSO, COA, and
while minimizing the unnecessary duplication of resources. Energy WOA, to achieve efficient resource scheduling and mitigate energy
consumption and reliability are closely intertwined concepts. In [48], consumption.
researchers explored this relationship and developed a model that The researchers proposed an innovative tasks scheduling algorithm
linked energy consumption to reliability levels. Their work aimed to leveraging the GWO technique for cloud computing environment [67].
maximize the reliability of parallel applications executed on uniproces- This GWO-based tasks scheduling (GWOTS) approach aimed to min-
sor systems while adhering to strict deadlines and energy consumption imize execution costs, reduce energy consumption, and shorten the
constraints. Authors in [49], proposed power management schemes overall makespan . Researchers developed an advanced multi-objective
for homogeneous multiprocessors that targeted energy savings while optimization technique inspired by the GWO to address the growing
upholding specified system reliability levels. computational demands on cloud data centers [68]. Their primary goals
Metaheuristic techniques are versatile methods inspired by natu- were to maximize the efficient utilization of cloud resources, minimize
ral phenomena, such as evolutionary adaptation, biological swarms, energy consumption, and reduce the overall execution time, while
3
Karishma and H. Kumar Computer Standards & Interfaces 97 (2026) 104106
Table 1
Performance parameters of various WOA based metaheuristic tasks scheduling techniques.
S. No. Reference Core technique Environment Considered parameters
Energy Reliability 𝐶𝑇𝑇 𝐴 Sensitivity Makespan Resource utilization
1 [72] VWOA Heterogeneous
2 [73] WOA Heterogeneous
3 [74] M-WODE Heterogeneous
4 [75] WOA Heterogeneous
5 [76] h-DEWOA Heterogeneous
6 [77] IWC Homogeneous
7 [24] HGWWO Heterogeneous
8 [78] HWOA based MBA Homogeneous
9 [79] HPSWOA Heterogeneous
10 [80] CWOA Heterogeneous
11 [81] HWOA Heterogeneous
12 [82] WHOA Heterogeneous
13 [83] ANN-WOA Homogeneous
14 [84] WOA Heterogeneous
15 Proposed model HWWO Heterogeneous
ensuring the requested services were delivered effectively. In [69], au- ranging from 30 m in length and weighting up to 180 tons. These
thors proposed a novel hybrid model that combined PSO and GWO for giants of the sea are classified into various species, including the killer
workflow scheduling in cloud computing environments. This integrated whale, the sei, the finback, the humpback, the minke, and the awe-
approach aimed to enhance the overall performance by optimizing total inspiring blue whale. Beyond their sheer size, whales are remarkable
execution costs and reducing the time required for task completion . for their intelligence and emotional depth, exhibiting complex social
The article [70] addressed the challenges of tasks allocation and quality behaviors. They are often observed traveling and living in close-knit
of service (QoS) optimization in cloudfog computing environment. groups. One of the most fascinating species is the humpback whale,
The authors proposed a multi-objectives GWO algorithm, implemented
renowned for its intricate hunting technique known as bubble-net
within the fog broker system, to minimize delay and energy consump-
feeding [85]. When it comes to hunting, humpback whales exhibit a
tion. In article [71], authors addressed tasks scheduling challenges in
remarkable preference for preying on schools of krill or small fish that
cloud computing by proposing a GWO-based algorithm. The approach
congregate near the oceans surface. Their intricate hunting strategy
aimed to efficiently allocate resources and minimize task completion
times. involves diving to depths of around 12 m and then employing a
WOA employs simple yet powerful search mechanisms to efficiently fascinating maneuver. The whales release a spiral of bubbles, carefully
identify optimal solutions. However, like other SI algorithms, WOA can encircling their prey, and then gracefully swim upwards towards the
face challenges such as getting trapped in local optima and maintaining surface, trapping their quarry within the bubble net. It is notewor-
population diversity. To address these limitations, numerous WOA thy that this bubble-net feeding technique is a unique behavior that
variants have been proposed, enhancing the core algorithm through has been observed exclusively in humpback whales. The exceptional
modifications or hybridization. These improved versions have been hunting prowess of these whales has served as a source of inspiration
successfully applied to a variety of optimization problems, including for the development of a swarm intelligence algorithm known as the
task scheduling in distributed computing environment. WOA [28]. Proposed for solving continuous optimization problems,
Table 1 provides a concise summary of recent studies that utilize the WOA aims to mimic the humpback whales remarkable hunting
WOA-based metaheuristic techniques for task scheduling in distributed strategies. The WOA represents each potential solution as a whale
systems. The table categorizes these approaches based on key per- searching for the optimal position, guided by the best solution found.
formance parameters, such as energy consumption, reliability, 𝐶𝑇𝑇 𝐴 ,
It uses two mechanisms: encircling the prey (exploring promising
sensitivity, makespan, and resource utilization. These parameters are
areas) and creating bubble nets (exploiting by trapping targets). As
chosen for their relevance in evaluating the proposed HWWO method in
depicted in Fig. 1, humpback whales exhibit a remarkable coordi-
this article. As evident from Table 1, while many studies consider these
nated feeding strategy involving the creation of bubble nets to trap
parameters individually or in limited combinations, none evaluate them
as comprehensively as we have done in this work. This underscores and capture their prey. The exploration phase searches for potential
the uniqueness of our approach and its potential to provide a more solution regions, while exploitation focuses on the most viable solutions
well-rounded assessment of task scheduling optimization. within those areas, balancing exploration and exploitation for efficient
optimization
3. Preliminaries
The following discussion aims to provide a succinct yet comprehen- 3.1.1. A mathematical-based model
sive understanding of the core concepts driving the WOA and GWO This section initially models the whale behaviors of encircling tar-
metaheuristics. Additionally, it shall elucidate the distinctive features gets, prey searching, and spiral bubble-net feeding maneuvers mathe-
of these algorithms and their versatile applicability across a wide matically.
spectrum of problem spaces.
3.1.1.1. Encircling prey. The WOA algorithm takes inspiration from the
3.1. Whale optimization algorithm hunting behavior of humpback whales, which can effectively locate and
encircle prey. Since the optimal solutions position is not known ini-
Whales are majestic creatures that captivate the imagination. Among tially, the algorithm assumes the current best solution is near the global
the animal kingdom, they hold the distinction of being the largest optimum. The other candidate solutions then attempt to update their
mammals on earth. An adult whale can reach staggering proportions, positions towards this best solution identified so far. This encircling and
4
Karishma and H. Kumar Computer Standards & Interfaces 97 (2026) 104106
Fig. 1. Coordinated feeding strategy employed by humpback whales involving bubble nets.
localization process is mathematically modeled through Eqs. (1) and 𝜈 signifies a randomly generated scalar quantity constrained
(2). within the bounds of [1, 1].
→ → → → → → →
𝐷 = | 𝜉 𝑍 (𝑟) 𝑍(𝑟)| (1) 𝐷 = |𝑍 (𝑟) 𝑍(𝑟)| (6)
→ → → → → → →
𝑍(𝑟 + 1) = |𝑍 (𝑟) 𝜁 𝐷| (2) 𝑍(𝑟 + 1) = 𝐷 𝑒 𝑏𝜈
𝑐𝑜𝑠(2𝜋𝜈) + 𝑍 (𝑟) (7)
The Eqs. (1) and (2) involve several variables and vectors. The variable
→ →
𝑟 denotes the current iteration number. 𝜁 and 𝜉 represent coefficient The humpback whale circles its prey in a tightening spiral pattern while
hunting. The WOA models this by randomly choosing between the
vector quantities. The vector 𝑍 representing the current best solution
shrinking encirclement or spiral model, each with 50% probability, to
must be updated during any iteration where a superior solution is
→ update whale positions during optimization. This stochastic positional
identified. The vector 𝑍 indicates another position vector being consid-
update process is given by Eq. (8), wherein 𝑝 denotes a randomly
ered. The absolute value operation is represented by the ∥ symbol. The
→ → generated scalar confined within the range [0,1].
calculation of the coefficient vectors 𝜁 and 𝜉 proceeds in the following
manner [85]: ⎧ → → →
→ ⎪ 𝑍 (𝑟) 𝜁 𝐷 if 𝑝 < 0.5
→ → → → 𝑍(𝑟 + 1) = ⎨ → (8)
𝜁 = 2 𝜇 𝑙1 𝜇 (3) ⎪ 𝐷 𝑒𝑏𝜈 𝑐𝑜𝑠(2𝜋𝜈) + 𝑍 (𝑟) if 𝑝 ≥ 0.5
→ →
𝜉 = 2 𝑙2 (4) 3.1.1.3. Exploration phase (searching for prey strategy). This strategy
→ facilitates the whales in surveying the problem domain to uncover
In Eq. (3), the parameter 𝜇 linearly decreases from 2 to 0 across all
unexplored regions and augment the diversity within the population. A
iterations, encompassing the exploration and exploitation phases, while
→ randomly selected search agent dictates the positional update for each
𝑙1 , 𝑙2 are random vectors in the range [0, 1]. The formulation of 𝜇 can →
be expressed as [2]: individual whale. The parameter 𝜁 enables steering the search agent
{ } away from an arbitrarily chosen humpback whale. The exploration
→ 2
𝜇 =2𝑟 (5) phase, governed by Eq. (10), prevents the premature convergence to
𝑚𝑎𝑥_ 𝑖𝑡𝑒𝑟𝑎𝑡𝑖𝑜𝑛
local optima [28].
3.1.1.2. Exploitation phase (bubble-net attacking method). Two distinct → → →
methodologies have been proposed aimed at constructing mathematical 𝐷 = |𝜉 𝑍 𝑟𝑎𝑛𝑑 𝑍(𝑟)| (9)
→ → →
models to characterize the bubble-net feeding behavior exhibited by
𝑍(𝑟 + 1) = 𝑍 𝑟𝑎𝑛𝑑 𝜁 𝐷 (10)
humpback whales.
i Shrinking encircling mechanism: This behavior is modeled by where, 𝑍 𝑟𝑎𝑛𝑑 denotes a randomly selected whale position vector from
→ the current population within the search space.
diminishing the convergence parameter 𝜇 in Eq. (3). Moreover,
→ →
the oscillation range of 𝜁 contracts linearly via 𝜇, transitioning
→ 3.2. Grey wolf optimization algorithm
from 2 to 0 across iterations. Stated differently, 𝜁 represents a
random value within the interval [−𝜇, 𝜇]. The GWO is a SI technique that emulates the hierarchical leadership
ii Spiral updating position mechanism: The approach structure and cooperative hunting strategies exhibited by grey wolves
commences by quantifying the distance between the vector 𝑍 , in their natural habitats [29]. The GWO algorithm mathematically
representing the best solution identified thus far, and another formalizes the search, encirclement, and attack behaviors observed in
whale position vector 𝑍, through Eq. (6). Subsequently, it de- the predatory conduct of grey wolves. It incorporates the hierarchical
fines the spiral motion pattern originating from the present social structure present within wolf packs as a core concept. Wolves
location and progressing towards an enhanced solution, as ex- are classified into four distinct hierarchical tiers based on their levels
pressed through Eq. (7). In these equations, the constant 𝑏 of dominance. The 𝛼, 𝛽, and 𝛿 ranks represent the leaders, presumed
governs the logarithmic spirals geometric characteristics, while to possess superior capabilities that guide the pack. In contrast, the 𝜔
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Karishma and H. Kumar Computer Standards & Interfaces 97 (2026) 104106
Fig. 2. Organizational structure and role hierarchy in grey wolf packs.
wolves assume a subordinate role, following the navigation directives 3.2.2. Hunting
provided by the dominant leaders (see Fig. 2). The grey wolf algorithm mimics the intricate hunting strategies
GWO employs mathematical models that emulate the intricate hunt- employed by wolf packs in nature. Central to this optimization process
ing tactics exhibited by grey wolves, including their pursuit, encir- is the 𝛼 wolf, acting as the lead entity guiding the search for the optimal
clement, and eventual capture of prey, as a framework to guide the solution. Through iterative refinement, the 𝛼 continuously updates and
optimization process. stores the best solution encountered, replacing it with an improved
one if found in subsequent iterations. This iterative refinement allows
3.2.1. Social behavior convergence towards the optimal result. While the 𝛼 takes the lead, the
The mathematical formulation supposes 𝛼 to be the preeminent 𝛽 and 𝛿 wolves contribute their prowess to the hunt. By mathematically
solution, embodying the social behavior of the lead wolf. The subse- simulating the hunting behavior, the algorithm assumes that the 𝛼, 𝛽,
quent solutions, 𝛽 and 𝛿, constitute the second and third-best outcomes, and 𝛿 solutions possess superior knowledge of the potential optimal
respectively. All remaining solutions are collectively classified as 𝜔. The position. Consequently, the top three candidate solutions are retained.
hunting process within the GWO algorithm is steered by the triumvirate The remaining search agents, including 𝜔, must update their positions
of 𝛼, 𝛽, and 𝛿, while the 𝜔 solutions are governed by adherence to this based on the 𝛼 location. In essence, the 𝛼, 𝛽, and 𝛿 predict the optimal
leading trio. location, while other wolves randomly explore the surrounding areas,
Encircling the prey: The predatory strategy of grey wolves involves driven by the overarching goal of locating the prey — the global opti-
meticulously encircling and confining their prey during the hunt. This mum. The positions of the wolves are iteratively updated through the
critical stage of encirclement is mathematically modeled by the ensuing subsequent mathematical equations that emulate the hunting behavior.
system of equations: → → → → ⎫
→ → → → 𝛶𝛼 = | 𝜉 1 𝑍 𝛼 𝑍| ⎪
𝛶 = | 𝜉 𝑍 𝑝 (𝑟) 𝑍(𝑟)| (11) → → → → ⎪
𝛶𝛽 = | 𝜉 2 𝑍 𝛽 𝑍| ⎬ (13)
→ → → → → → → → ⎪
𝑍(𝑟 + 1) = 𝑍 𝑝 (𝑟) 𝜁 𝛶 (12) 𝛶𝛿 = | 𝜉 3 𝑍 𝛿 𝑍| ⎪
→ → → → →
In the given context, the variable 𝛶 symbolizes the vector distance 𝑍1 = 𝑍𝛼 𝜁 1 𝛶 𝛼 (14)
separating the preys location from the wolfs position. The variable → → → →
𝑟 denotes the current iteration number, while (𝑟 + 1) signifies the 𝑍2 = 𝑍𝛽 𝜁 2 𝛶 𝛽 (15)
→ → → →
iteration number that follows. The variable 𝑍 𝑝 (𝑟) signifies the position 𝑍3 = 𝑍𝛿 𝜁 3 𝛶 𝛿 (16)
of the prey within the optimization process, whereas 𝑍(𝑟) denotes → → →
𝑍1 + 𝑍2 + 𝑍3
the position of the wolf. These variables are employed to model the 𝑍(𝑟 + 1) = (17)
interaction between the prey and the wolf, which is a crucial aspect of 3
the optimization algorithm being discussed.
The optimization algorithm iteratively calculates and refines the 3.2.3. Exploitation (attacking prey)
→ →
coefficient vectors 𝜁 and 𝜉 through the use of the mathematical ex- The hunting process involves a strategy employed by the grey
pressions represented by Eqs. (3) and (4), which are provided as wolves to restrict the preys mobility, rendering it vulnerable to an
follows: attack. This approach is implemented by gradually decreasing the value
→ → → → → → of a parameter 𝜇(decrease from 2 to 0). Concurrently, the value of
𝜁 = 2 𝜇 𝑙1 𝜇 and 𝜉 = 2 𝑙2
another parameter, 𝜁 , is also reduced in accordance with the value of
→ →
where, the parameter 𝜇 linearly decreases from 2 to 0 across all 𝜇, ensuring it remains within the range of [1, 1]. The grey wolves
iterations, encompassing the exploration and exploitation phases, while initiate an attack on the prey when the value of 𝜁 falls between 1
𝑙1 , 𝑙2 are random vectors in the range [0, 1]. and 1.
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Karishma and H. Kumar Computer Standards & Interfaces 97 (2026) 104106
Fig. 3. Dynamic positioning of search agents based on parameter interactions.
3.2.4. Exploration (search for prey) Table 2
The lead wolves, 𝛼, 𝛽, and 𝛿, strategically position themselves in Key symbols for the present work.
a manner that balances the pursuit of the prey with the readiness to Notation Description
strike. This dual approach is modeled through a parameter 𝜁 , where 𝐺 Direct acyclic graph (DAG) representing the
distributed parallel application
values exceeding 1 represent a diversion from the preys immediate
𝑋 = {𝜏1 , 𝜏2 , … , 𝜏|𝑋 } Set of |𝑋| tasks
vicinity, yet still within striking range. Another influential factor gov- 𝑌 = {𝑌1 , 𝑌2 , … , 𝑌|𝑌 | } Set of |𝑌 | processors
erning the exploration process is denoted by 𝜉 , which plays a crucial 𝑐̂𝑖,𝑘 Worst-case response time between the tasks 𝜏1 and 𝜏𝑘
𝑤̂ 𝑖,𝑙 Worst-case execution time of the task 𝜏𝑖 on the
role, particularly in scenarios where the algorithm encounters local
→ processor 𝑌𝑙
optima. The range of 𝜉 lies between 0 and 2, and its value is determined LB(G) Lower bound of G
through a mathematical expression, labeled as Eq. (4). DL(G) Deadline of application G
MS(G) Makespan of application G
Fig. 3 illustrates a search agent dynamically positioning itself within
𝐸̂ 𝑠 (𝐺) Static energy consumption of G
a search space using 𝛼, 𝛽, and 𝛿 parameters. The agents final po- 𝐸̂ 𝑑 (𝜏𝑖 , 𝑌𝑙 , 𝑓𝑙, ) The dynamic energy consumption of task𝜏𝑖 on
sition, representing an estimated prey location, is depicted within a processor 𝑌𝑙 with frequency 𝑓𝑙,
circle defined by these parameters. Surrounding agents adapt their 𝐸̂ 𝑑 (𝐺) Dynamic energy consumption of G
positions around this estimated location, introducing randomness and 𝐸̂ 𝑡𝑜𝑡𝑎𝑙 (𝐺) The aggregate energy consumption of G
𝑅𝑒 (𝐺) Reliability of the application G
coordinated behavior akin to predators.
𝑅𝑒 (𝜏𝑖 , 𝑌𝑙 , 𝑓𝑙, ) Reliability of task 𝜏𝑖 executed on the 𝑌𝑙 with
frequency 𝑓𝑙,
4. Notations and mathematical modeling 𝑅𝑒(𝑚𝑖𝑛) (𝐺) Minimum reliability value of G
𝑅𝑒(𝑚𝑎𝑥) (𝐺) Maximum reliability value of G
𝑅𝑒(𝑔𝑜𝑎𝑙) (𝐺) Reliability goal of the application G
4.1. Notations
𝜆𝑙, Failure rate of processor 𝑌𝑙 at frequency 𝑓𝑙,
𝑅𝑒(𝑚𝑖𝑛) (𝜏𝑖 ) Minimum reliability value of 𝜏𝑖
The key symbols and their meanings, as employed in the present 𝑅𝑒(𝑚𝑎𝑥) (𝜏𝑖 ) Maximum reliability value of 𝜏𝑖
work, are summarized in Table 2. 𝑅𝑒 (𝜏𝑖 ) Reliability of task 𝜏𝑖
𝐸𝑆𝑇 (𝜏𝑘 , 𝑌𝑙 ) Earliest start time of 𝑘th task on processor 𝑌𝑙
𝐸𝐹 𝑇 (𝜏𝑘 , 𝑌𝑙 ) Earliest finish time of 𝑘th task on processor 𝑌𝑙
4.2. Application model
𝐴𝐹 𝑇 (𝜏𝑘 ) Actual finish time of 𝑘th task
The directed acyclic graph (DAG) serves as a versatile represen-
tation widely adopted in academic research for modeling distributed
parallel applications. In this study, the application is effectively mod- zero-weight dependencies are introduced into the graph to maintain
eled as a DAG, denoted as 𝐺 = (𝑋, 𝐸, ̂ 𝑊̂ , 𝐶).
̂ This model encompasses consistency [8]. For |𝑌 | no. of processors, 𝑤̂ 𝑖,𝑙 ∈ 𝑊̂ |𝑋|×|𝑌 | gives the
a set 𝑋, comprising various computational tasks with distinct worst- 𝑊̂ 𝐶𝐸𝑇 of task 𝜏𝑖 on processor 𝑌𝑙 .
case execution times (𝑊̂ 𝐶𝐸𝑇 𝑠) on different processors. Furthermore, The expressions LB(G) and DL(G) represent the lower bound and
the model incorporates a set 𝐸, ̂ representing communication edges
deadline of G, respectively. It is imperative to maintain a condition
between these tasks. Each element in 𝐸, ̂ represented as 𝑒̂𝑖,𝑘 , signifies
wherein the lower bound of an application remains below its associated
a communication link from task 𝜏𝑖 to 𝜏𝑘 , accompanied by a precedence
deadline, i.e., 𝐿𝐵(𝐺) ≤ 𝐷𝐿(𝐺) In the course of this work, the concept of
constraint that mandates task 𝜏𝑘 to commence only upon the com-
lower bound pertains to the minimal achievable makespan by an appli-
pletion of task 𝜏𝑖 . Consequently, every 𝑐̂𝑖,𝑘 represents the worst-case
response time (𝑊̂ 𝐶𝑅𝑇 ) of 𝑒̂𝑖,𝑘 . The set 𝑠𝑢𝑐𝑐(𝜏𝑖 ) represents the immediate cation developed through a conventional scheduling algorithm, where
successor tasks of 𝜏𝑖 , and 𝑝𝑟𝑒𝑑(𝜏𝑖 ) represents the immediate predecessor each processor is singularly dedicated to the application, operating at
tasks of 𝜏𝑖 . Tasks lacking predecessors are designated as 𝜏𝑒𝑛𝑡𝑟𝑦 , while its maximum frequency [36,86]. 𝑀𝑆(𝐺) denotes the actual makespan
those lacking successors are designated as 𝜏𝑒𝑥𝑖𝑡 . In instances where achieved by application G, which signifies the precise conclusion time
a function includes multiple 𝜏𝑒𝑛𝑡𝑟𝑦 or 𝜏𝑒𝑥𝑖𝑡 tasks, dummy tasks with of 𝜏𝑒𝑥𝑖𝑡 within the corresponding 𝐷𝐴𝐺.
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Karishma and H. Kumar Computer Standards & Interfaces 97 (2026) 104106
Fig. 4. Example of a DAG featuring 10 tasks.
Table 3 exhibits a dependency on frequency. The parameter 𝜙 signifies the
(𝑊̂ 𝐶𝐸𝑇 𝑠) of tasks in Fig. 4. system states and serves as an indicator of whether dynamic power is
Tasks \Processors 𝑌1 𝑌2 𝑌3 presently being consumed within the system, where 𝜙 = 1 signifies an
𝜏1 14 16 9 active state, and 𝜙 = 0 represents an inactive condition. The term 𝐶𝑒𝑓
𝜏2 13 19 18 symbolizes the effective switching capacitance. The exponent m, known
𝜏3 11 13 19
𝜏4 13 8 17
as the dynamic power exponent with a minimum value of 2. Both 𝐶𝑒𝑓
𝜏5 12 13 10 and m are processor-specific constants.
𝜏6 13 16 9 Strategically reducing the operating frequency presents an avenue
𝜏7 7 15 11 to curb frequency-dependent power dissipation. However, prolonged
𝜏8 5 11 14
𝜏9 18 12 20
execution times may ensue, augmenting static power consumption and
𝜏10 21 7 16 frequency-independent power expenditure. Several studies, including
those conducted by [8,87], and [88], have established the existence
of an optimal energy-efficient frequency, denoted as 𝑓𝑒𝑒 , at which the
system achieves minimal power consumption. This optimal frequency
Fig. 4 illustrates a DAG-based parallel application as an example [8,
can be formulated as follows:
86]. This demonstration comprises 10 tasks processed across three √
designated processors {𝑌1 , 𝑌2 , 𝑌3 }. In the illustration, the weight of 18 𝑃𝑖𝑛𝑑
𝑓𝑒𝑒 = 𝑚 (19)
on the edge 𝑒̂1,2 connecting 𝜏1 and 𝜏2 symbolizes the response time, (𝑚 1)𝐶𝑒𝑓
denoted as 𝑐̂1,2 , if 𝜏1 and 𝜏2 are not allocated to the same processor.
The data in Table 3 represents the worst-case execution times Under the premise that a processors operating frequency can vary
(𝑊̂ 𝐶𝐸𝑇 𝑠) corresponding to the maximum frequency illustrated in Fig. between a minimum available frequency, 𝑓𝑚𝑖𝑛 , and a maximum fre-
4. The value of 14 assigned to the intersection of 𝜏1 and 𝑌1 in Table quency, 𝑓𝑚𝑎𝑥 , the optimal energy-efficient frequency for executing a
3 denotes the (𝑊̂ 𝐶𝐸𝑇 𝑠), symbolized as 𝑤̂ 1,1 = 14. The variations in given task should adhere to the following formulation:
(𝑊̂ 𝐶𝐸𝑇 𝑠) for an identical task across different processors arise from
𝑓𝑙𝑜𝑤 = 𝑚𝑎𝑥(𝑓𝑒𝑒 , 𝑓𝑚𝑖𝑛 ) (20)
the intrinsic diversity of the processors.
As a result, any of the actual effective frequencies, denoted as 𝑓 ,
4.3. Power and energy models should reside within the range delineated by 𝑓𝑙𝑜𝑤𝑓 ≤ 𝑓𝑚𝑎𝑥 [8].
For a system with |𝑌 | heterogeneous processors, each processor
Considering the nearly linear correlation between voltage and fre-
requires individual power parameters. Here, the static power set is
quency, DVFS techniques are employed to scale down these parameters,
defined as:
thereby achieving energy conservation. Consistent with the approaches
adopted in [8,87], the term frequency change is utilized to denote {𝑃1,𝑠 , 𝑃2,𝑠 , … , 𝑃|𝑌 |,𝑠 }
the simultaneous alteration of both voltage and frequency. For DVFS-
capable systems, a widely adopted system-level power model, as ex- frequency-independent and dependent dynamic power sets are repre-
emplified in [8,87], is leveraged. This model expresses the power sented as:
consumption at a given frequency (f) as follows:
{𝑃1,𝑖𝑛𝑑 , 𝑃2,𝑖𝑛𝑑 , … , 𝑃|𝑌 |,𝑖𝑛𝑑 } and {𝑃1,𝑑 , 𝑃2,𝑑 , … , 𝑃|𝑌 |,𝑑 }
𝑃 (𝑓 ) = 𝑃𝑠 + 𝜙(𝑃𝑖𝑛𝑑 + 𝑃𝑑 ) = 𝑃𝑠 + 𝜙(𝑃𝑖𝑛𝑑 + 𝐶𝑒𝑓 𝑓 𝑚 ) (18)
the effective switching capacitance is defined as:
Within this power model, 𝑃𝑠 symbolizes the static power component,
which can be mitigated solely by deactivating the entire system. The {𝐶1,𝑒𝑓 , 𝐶2,𝑒𝑓 , … , 𝐶|𝑌 |,𝑒𝑓 }
frequency-independent dynamic power is represented by 𝑃𝑖𝑛𝑑 , and this lowest energy-efficient frequency set is represented as:
component can be eliminated by transitioning the system into a low-
power sleep state. 𝑃𝑑 denotes the dynamic power component that {𝑓1,𝑙𝑜𝑤 , 𝑓2,𝑙𝑜𝑤 , … , 𝑓|𝑌 |,𝑙𝑜𝑤 }
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Karishma and H. Kumar Computer Standards & Interfaces 97 (2026) 104106
and actual effective frequency set is: To determine the applications reliability bounds, an evaluation across
{ all available processors is conducted. The minimum and maximum
{𝑓1,𝑙𝑜𝑤 , 𝑓1,𝑐 , 𝑓1,𝑑 , … , 𝑓1,𝑚𝑎𝑥 }, {𝑓2,𝑙𝑜𝑤 , 𝑓2,𝑐 , 𝑓2,𝑑 , … , 𝑓2,𝑚𝑎𝑥 }, …
} reliability values are then derived using the respective equations:
{𝑓|𝑌 |,𝑙𝑜𝑤 , 𝑓|𝑌 |,𝑐 , 𝑓|𝑌 |,𝑑 , … , 𝑓|𝑌 |,𝑚𝑎𝑥 }
𝑅𝑒(𝑚𝑖𝑛) (𝜏𝑖 ) = min 𝑅𝑒 (𝜏𝑖 , 𝑌𝑙 , 𝑓𝑙,𝑙𝑜𝑤 ) (30)
𝑌𝑙 ∈𝑌
Let 𝐸̂ 𝑠 (𝐺) denote the static energy consumed by active processors ∏
executing application G. Since inactive processors do not consume 𝑅𝑒(𝑚𝑎𝑥) (𝜏𝑖 ) = 1 (1 𝑅𝑒 (𝜏𝑖 , 𝑌𝑙 , 𝑓𝑙,𝑚𝑎𝑥 )) (31)
energy, 𝐸̂ 𝑠 (𝐺) is the sum of static energy consumption across all active 𝑌𝑙 ∈𝑌
processors, calculated as: As per Eq. (29), the reliability of application G is the product of task
|𝑌 |
∑ reliabilities. Hence the minimum and maximum reliability values of G
( )
𝐸̂ 𝑠 (𝐺) = 𝑃𝑙,𝑠 𝑀𝑆(𝐺) (21) can be computed as:
𝑙=1,𝑌𝑙 is on ∏
𝑅𝑒(𝑚𝑖𝑛) (𝐺) = (𝜏𝑖 ) (32)
The dynamic power consumption of task 𝜏𝑖 executing on 𝑌𝑙 at frequency
𝑒(𝑚𝑖𝑛)
𝑓𝑙, is represented by 𝑃𝑑 (𝜏𝑖 , 𝑌𝑙 , 𝑓𝑙, ). This can be formulated as: ∏
𝑅𝑒(𝑚𝑎𝑥) (𝐺) = (𝜏𝑖 ) (33)
𝑚
𝑃𝑑 (𝜏𝑖 , 𝑌𝑙 , 𝑓𝑙, ) = (𝑃𝑙,𝑖𝑛𝑑 + 𝐶𝑙,𝑒𝑓 𝑓𝑙,𝑙 ) (22) 𝑒(𝑚𝑎𝑥)
The application is deemed reliable if its reliability metric satisfies the
And the dynamic energy consumption of 𝜏𝑖 is calculated as:
specified reliability goal, denoted as 𝑅𝑒(𝑔𝑜𝑎𝑙) (𝐺) i.e.,
𝑚 𝑓𝑙,𝑚𝑎𝑥
𝐸̂ 𝑑 (𝜏𝑖 , 𝑌𝑙 , 𝑓𝑙, ) = (𝑃𝑙,𝑖𝑛𝑑 + 𝐶𝑙,𝑒𝑓 𝑓𝑙,𝑙 ) 𝑤̂ 𝑖,𝑙 (23)
𝑓𝑙, 𝑅𝑒(𝑚𝑖𝑛) (𝐺) ≤ 𝑅𝑒(𝑔𝑜𝑎𝑙) (𝐺) ≤ 𝑅𝑒(𝑚𝑎𝑥) (𝐺) (34)
Let 𝐸̂ 𝑑 (𝐺) represent the total dynamic energy consumption of applica-
tion G, calculated as the sum of dynamic energy consumed by each 4.5. Description of scheduling problem
task.
|𝑋|
∑ The focus of this subsection is on the tasks scheduling problem
𝐸̂ 𝑑 (𝐺) = 𝐸̂ 𝑑 (𝜏𝑖 , 𝑌𝑎𝑐(𝑖) , 𝑓𝑎𝑐(𝑖),𝑧(𝑖) ) (24) in distributed computing environments consisting of parallel applica-
𝑖=1 tions G and heterogeneous processor set Y. Specifically, it addresses a
where 𝑌𝑎𝑐(𝑖) signifies the processor and 𝑓𝑎𝑐(𝑖),𝑧(𝑖) represents the fre- scenario where tasks must be executed on a set Y of processors that
quency at which task 𝜏𝑖 is actively executing. support varying frequency levels. This assignment must simultaneously
Hence, the aggregated energy consumption of G can be deduced optimize two critical objectives: minimizing overall energy consump-
using the ensuing formulation: tion and ensuring the applications reliability metric 𝑅𝑒 (𝐺) meets or
surpasses a predefined reliability goal, 𝑅𝑒(𝑔𝑜𝑎𝑙) (𝐺). Ultimately, the goal
𝐸̂ 𝑡𝑜𝑡𝑎𝑙 (𝐺) = 𝐸̂ 𝑠 (𝐺) + 𝐸̂ 𝑑 (𝐺) (25)
is to judiciously map tasks to processor-frequency combinations that
strike an optimal balance between reducing energy usage and boosting
4.4. Reliability model and reliability goal system reliability for the given application.
𝐸̂ 𝑡𝑜𝑡𝑎𝑙 (𝐺) = 𝐸̂ 𝑠 (𝐺) + 𝐸̂ 𝑑 (𝐺)
The concept of processor reliability probability adhering to a Pois- ∏
son distribution has been extensively studied and widely accepted subject to: 𝑅𝑒 (𝐺) = 𝑅𝑒 (𝜏𝑖 ) ≥ 𝑅𝑒(𝑔𝑜𝑎𝑙) (𝐺)
𝜏𝑖 ∈𝑋
within the relevant literature [8]. The variable 𝜆𝑙 denotes the failure
rate per unit time of processor 𝑌𝑙 and the reliability of a task 𝜏𝑖 executed
5. Proposed hybrid approach
on processor 𝑌𝑙 within its 𝑊̂ 𝐶𝐸𝑇 can be quantified using the following
mathematical expression:
This study presents an inventive methodology that seamlessly inte-
𝑅𝑒 (𝜏𝑖 , 𝑌𝑙 ) = 𝑒−𝜆𝑙 ∗𝑤̂ 𝑖,𝑙 (26) grates the HWWO algorithm and the DVFS technique, addressing the
crucial need for energy-efficient tasks scheduling strategies that can
For DVFS-enabled processors, research shows varying failure rates
adeptly address both static and dynamic energy considerations. The
across frequencies. Let 𝜆𝑙,𝑚𝑎𝑥 denote the failure rate of processor 𝑌𝑙 at
dynamic adjustment of processor voltage and frequency, facilitated by
maximum frequency. Then, the failure rate 𝜆𝑙, of 𝑌𝑙 at frequency 𝑓𝑙,
the DVFS mechanism, enables energy consumption optimization during
is calculated as:
task execution. This integrated methodology possesses the potential
𝑑(𝑓𝑙,𝑚𝑎𝑥 𝑓𝑙, )
to revolutionize tasks scheduling in computational environments by
𝜆𝑙, = 𝜆𝑙,𝑚𝑎𝑥 10 𝑓𝑙,𝑚𝑎𝑥 𝑓𝑙,𝑚𝑖𝑛 (27)
achieving substantial energy savings, enhancing system reliability, and
Where the constant d indicates the sensitivity of failure rates to voltage concurrently optimizing computational time. The HWWO algorithm
scaling. employs a mutation operator in conjunction with an insert-reversed
Subsequently, a correlation is established between task reliability block operation, contributing to the minimization of static energy
and frequency, as outlined by Eqs. (26) and (27) i.e., the reliability consumption. Complementing this, the DVFS technique is strategically
of the task 𝜏𝑖 executed on the processor 𝑌𝑙 with the frequency 𝑓𝑙, is employed to tackle dynamic energy consumption, further augment-
calculated as follows: ing the energy-efficiency of the proposed solution. The incorporation
𝑤̂ 𝑓
−𝜆𝑙, 𝑖,𝑙 𝑓 𝑙,𝑚𝑎𝑥
of the WOA and the GWO into the task assignment methodology is
𝑅𝑒 (𝜏𝑖 , 𝑌𝑙 , 𝑓𝑙, ) = 𝑒 𝑙,
substantiated by their exceptional versatility. These techniques have
𝑑(𝑓𝑙,𝑚𝑎𝑥 𝑓𝑙, ) consistently exhibited superior performance in addressing assignment
𝑤̂ 𝑓
−𝜆𝑙,𝑚𝑎𝑥 10 𝑓𝑙,𝑚𝑎𝑥 𝑓𝑙,𝑚𝑖𝑛 𝑖,𝑙 𝑓 𝑙,𝑚𝑎𝑥
=𝑒 𝑙, (28) issues, demonstrating remarkable convergence characteristics [89].
In any SI algorithm, achieving a balance between exploitation and
The overall reliability of an application can be expressed as the product exploration is crucial for its effectiveness in terms of convergence
of the reliability values associated with each of its constituent tasks. The speed and solution quality. As underscored in [30], the WOA algorithm
reliability value of the application G is denoted as: showcases remarkable performance regarding convergence speed while
∏ adeptly balancing exploration and exploitation in addressing optimiza-
𝑅𝑒 (𝐺) = 𝑅𝑒 (𝜏𝑖 ) (29)
𝜏𝑖 ∈𝑋 tion issues. Although the WOA demonstrates effectiveness compared
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Karishma and H. Kumar Computer Standards & Interfaces 97 (2026) 104106
to conventional algorithms, it may encounter challenges such as strug- 1. Determine task weights through the calculation of the average
gling to evade local optima because of its encircling search mechanism execution time across all processors, mirroring the HEFT algo-
and insufficient solution enhancement after each iteration. These limi- rithms methodology. In the HEFT algorithm, the function 𝑓 (𝑤̂ 𝑖 )
tations of WOA prompted the proposal of a hybrid approach with GWO. is computed by averaging the execution time of 𝜏𝑖 across each
GWO excels in exploitation, offering a solution to WOAs challenges machine, depicted as:
through two strategies: preserving the best solution per iteration and
𝑓 (𝑤̂ 𝑖 ) = 𝑎𝑣𝑟(𝑤̂ 𝑌1 , 𝑤̂ 𝑌2 , … , 𝑤̂ 𝑌|𝑌 | ) (36)
evaluating new solutions with the best one during exploration. If the
outcome improves upon the best solution, agents positions change; oth- 2. Alternatively, it can be derived from the best-case scenario.
erwise, they remain unchanged. Additionally, to enhance the HWWO
algorithm, authors proposed integrating mutation operators into WOA 𝑓 (𝑤̂ 𝑖 ) = min(𝑤̂ 𝑌1 , 𝑤̂ 𝑌2 , … , 𝑤̂ 𝑌|𝑌 | ) (37)
and combining it with GWO.
Mapping tasks to multiprocessors poses a significant NP-hard chal- 3. Task weighting based on the worst-case scenario.
lenge. Consequently, the hybrid metaheuristic HWWO scheduling tech- 𝑓 (𝑤̂ 𝑖 ) = max(𝑤̂ 𝑌1 , 𝑤̂ 𝑌2 , … , 𝑤̂ 𝑌|𝑌 | ) (38)
nique is employed as a strategic solution. This approach unfolds across
two distinct phases: initial task prioritization, wherein tasks are se-
Each of these schemes results in a unique task ordering. For instance,
quenced in descending order of priorities, and subsequent task alloca-
when applied to the DAG example shown in Fig. 4, they produce differ-
tion to suitable processors.
ent upward rank lists for tasks. The most optimal ranking is achieved
Phase 1 by the first scheme, the HEFT algorithm, with the corresponding values
for the tasks depicted in Fig. 4 summarized in Table 4.
5.1. Prioritizing tasks and deadline determination Upon employing the DVR HEFT technique to generate an optimized
upward rank list for the tasks, the next step involved calculating the
To calculate the lower bound for tasks scheduling, this study uti- computation time required to allocate each task to the available pro-
lizes the heterogeneous earliest-finish-time (HEFT) algorithm proposed cessors. This allocation process followed the methodology outlined in
by [86]. The HEFT algorithm is chosen due to its proven effective- the HEFT algorithm. The task with the highest rank value is identified
ness in generating high-quality schedules for heterogeneous computing and then assigned to the processor that could complete its execution
systems, making it a reliable choice for this purpose. Obtaining an at the earliest possible finish time (EFT). To determine the earliest
exact lower bound is a challenging endeavor, so the scheduling length feasible execution time for a given task 𝜏𝑘 on processor 𝑌𝑙 , the values
estimated by the HEFT method is adopted as the standard. It is further for the 𝐸𝑆𝑇 (𝜏𝑘 , 𝑌𝑙 ) (earliest start time) and 𝐸𝐹 𝑇 (𝜏𝑘 , 𝑌𝑙 ) are calculated
assumed that the applications deadline constraint is not known until recursively as follows:
after this lower bound reference has been determined. ⎧𝐸𝑆𝑇 (𝜏
𝑒𝑛𝑡𝑟𝑦,𝑌𝑙 ) = 0;
The strategic allocation of tasks stands as a pivotal challenge in ⎪
⎪ ⎧
the context of (DAG) list scheduling within heterogeneous distributed ⎨ ⎪𝑎𝑣𝑎𝑖𝑙[𝑙], (39)
systems. In an endeavor to tackle this challenge, the present article ⎪ 𝐸𝑆𝑇 (𝜏 ,
𝑘 𝑙𝑌 ) = 𝑚𝑎𝑥 ⎨ 𝑚𝑎𝑥 {𝐴𝐹 𝑇 (𝜏 ) + 𝑐̂ } ;
adopts the dynamic variant rank HEFT algorithm (DVR HEFT), as intro- ⎪ ⎪𝜏𝑖 ∈𝑝𝑟𝑒𝑑(𝜏𝑘 ) 𝑖 𝑖,𝑘
⎩ ⎩
duced by [90]. As per the findings elucidated by [90], the DVR HEFT
and 𝐸𝐹 𝑇 (𝜏𝑘 , 𝑌𝑙 ) = 𝐸𝑆𝑇 (𝜏𝑘 , 𝑌𝑙 ) + 𝑤̂ 𝑘,𝑙 (40)
algorithm demonstrates enhanced performance over its conventional
counterpart, HEFT, by yielding superior outcomes while concurrently The term 𝑎𝑣𝑎𝑖𝑙[𝑙] denotes the earliest moment when processor 𝑌𝑙 is
mitigating time complexity. By utilizing this improved task prioritiza- ready to execute a task, while 𝐴𝐹 𝑇 (𝜏𝑖 ) refers to the actual finish time of
tion approach, the DVR HEFT algorithm aims to enhance the efficiency task 𝜏𝑖 . If tasks 𝜏𝑖 and 𝜏𝑘 are allocated to the same processor, the vari-
of scheduling interdependent tasks across heterogeneous computing able 𝑐̂𝑖,𝑘 is assigned a value of zero. The makespan of the application de-
resources within a distributed system. In its initial phase, akin to other fines the exact completion time of task 𝜏𝑒𝑥𝑖𝑡 , accounting for the schedul-
static algorithms, the DVR HEFT algorithm undertakes the computation ing of all tasks within a DAG. As previously described, the process to
of task priorities. Within the DVR HEFT framework, this entails metic- compute the lower bound of application G unfolds as follows:
ulously establishing task priorities through a comprehensive evaluation
𝐿𝐵(𝐺) = 𝐿𝐵(𝜏𝑒𝑥𝑖𝑡 ) (41)
of their upward rank values, following a procedure similar to that of the
HEFT algorithm. The upward rank, denoted as 𝑅𝑎𝑛𝑘𝑈 (𝜏𝑖 ), for a given Therefore, the relative deadline can be fulfilled. For the illustrated
task 𝜏𝑖 , is recursively determined through the following equation: example in Fig. 4, the applications deadline is considered as the sum
{ } of its lower bound and 20 [86].
𝑅𝑎𝑛𝑘𝑈 (𝜏𝑖 ) = 𝑓 (𝑤̂ 𝑖 ) + max [𝑎𝑣𝑟(𝑐̂𝑖,𝑘 ) + 𝑅𝑎𝑛𝑘𝑈 (𝜏𝑘 )] (35) The comparative scheduling results for the specified DAG illustrated
𝜏𝑘 ∈𝑠𝑢𝑐𝑐(𝜏𝑖 )
in Fig. 4 have been determined using a variety of algorithms, including
where, the symbol 𝑤̂ 𝑖 represents the 𝑊̂ 𝐶𝐸𝑇 of task 𝜏𝑖 . The task weight HEFT [86], DECM [37], energy-aware processor merging (EPM) [91],
value, produced by the function 𝑓 (𝑤̂ 𝑖 ), is contingent upon the tasks reliability enhancement under energy and response time constraints
execution duration on each processor whereas 𝑐̂𝑖,𝑘 signifies the 𝑊̂ 𝐶𝑅𝑇 (REREC) [38], and energy-efficient scheduling with a reliability goal
between the tasks 𝜏𝑖 and 𝜏𝑘 . (ESRG) [8]. Assessing energy consumption and reliability involves ref-
In a heterogeneous computing environment, the time required to erencing the power parameters listed in Table 5 for all processors. Each
execute a task can fluctuate based on the capabilities and performance processors energy-efficient frequency, denoted as 𝑓𝑒𝑒 , is calculated
characteristics of the specific machine handling that task. As a result, in based on Eq. (19), while the maximum frequency, 𝑓𝑚𝑎𝑥 , for each proces-
such heterogeneous settings, there exist multiple distinct methodologies sor is considered to be 1.0, as indicated in previous studies [8,91]. The
to calculate the computational weight associated with each node or schedule generated by employing the HEFT algorithm at its maximum
task. The approach chosen to determine a nodes weight 𝑤̂ 𝑖 could frequency level is graphically presented in Fig. 5. The aggregate energy,
potentially optimize computation time in certain scenarios, however, denoted as 𝐸̂ 𝑡𝑜𝑡𝑎𝑙 (𝐺), and the overall reliability, represented as 𝑅𝑒 (𝐺),
it does not guarantee improvements across all cases. As a result, the resulting from the execution of the HEFT algorithm, are quantified as
researchers in [90] proposed three distinct methods for calculating the 170.52 and 0.880426, respectively [91]. The visual depictions of the
upward rank values assigned to tasks. These alternative schemes for scheduling outcomes for the other algorithms are illustrated in Figs.
determining task priorities are described as follows: 69. It is worth highlighting that the processors displayed with shading
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Karishma and H. Kumar Computer Standards & Interfaces 97 (2026) 104106
Table 4
𝑅𝑎𝑛𝑘𝑈 values for tasks illustrated in Fig. 4.
Tasks 𝜏1 𝜏3 𝜏2 𝜏4 𝜏5 𝜏6 𝜏7 𝜏8 𝜏9 𝜏10
𝑅𝑎𝑛𝑘𝑈 133.19 118.19 115.86 114.19 101.53 87.27 70.86 59.86 44.36 14.7
Fig. 5. Scheduling result of the DAG shown in Fig. 4 using the HEFT technique.
Fig. 6. Scheduling result of the DAG shown in Fig. 4 using the DECM technique.
Fig. 7. Scheduling result of the DAG shown in Fig. 4 using the EPM technique.
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Karishma and H. Kumar Computer Standards & Interfaces 97 (2026) 104106
Fig. 8. Scheduling result of the DAG shown in Fig. 4 using the REREC technique.
Fig. 9. Scheduling result of the DAG shown in Fig. 4 using the ESRG technique.
Table 5 employing the DVR HEFT technique. This method aids in reducing
Power parameters of processors (𝑌1 , 𝑌2 , 𝑎𝑛𝑑𝑌3 ). the static energy consumed. This section proposes a novel algorithmic
𝑌𝑙 𝑃𝑙,𝑠 𝐶𝑙,𝑒𝑓 𝑃𝑙,𝑖𝑛𝑑 𝑚𝑙 𝑓𝑙,𝑙𝑜𝑤 𝑓𝑙,𝑚𝑎𝑥 𝜆𝑙,𝑚𝑎𝑥 approach that leverages the DVFS-integrated EES technique. This algo-
𝑌1 0.3 0.8 0.06 2.9 0.33 1.0 0.0005 rithm incorporates a HWWO model, featuring an insert-reversed block
𝑌2 0.2 0.7 0.07 2.7 0.29 1.0 0.0002 operation and a mutation operator. The primary goal is to efficiently
𝑌3 0.1 1.0 0.07 2.4 0.29 1.0 0.0009
assign tasks to appropriate processors within computational environ-
ments, thereby achieving substantial reductions in energy consumption
while simultaneously enhancing the overall reliability of the system.
in the figures signify their inactive or idle status during the execution The mutation operators main role is to diversify the population and
of the respective schedules. boost HWWOs global exploration. This study employs the inversion
The tasks displayed in blue indicate a higher execution frequency. mutation operator to fulfill this function.
Initially, all processors shown in Fig. 6 and processors 𝑌1 and 𝑌2
illustrated in Fig. 7 become active. Following that, every processor 5.2.1. Termination criteria
depicted in Fig. 8 is activated. Afterward, Fig. 9 demonstrates the
Optimization algorithms must have proper stopping conditions to
activation of processors 𝑌1 and 𝑌2 specifically.
ensure they do not run indefinitely. The algorithm iterates until conver-
The total energy consumption when employing the DECM algorithm
gence to find the best solution, making it essential to set termination
(depicted in Fig. 6) is lower than other algorithms, followed by REREC
criteria to assess the optimization processs convergence. In this case,
and ESRG algorithms. Crucially, this technique also enhances the sys-
the algorithm is designed to carry out 20 optimization iterations ini-
tems reliability compared to these other methods. By analyzing Figs.
tially, before assessing any convergence criteria. Subsequent to this
59, it becomes evident that the DECM technique delivers superior per-
initial phase, it examines two criteria:
formance concerning both energy efficiency and reliability, surpassing
the EPM, HEFT, REREC, and ESRG algorithms. i The first criterion measures the change in the fitness function
Phase 2 between the latest optimization iteration 𝑓𝑓 𝑛 (𝑟) and the previous
iteration 𝑓𝑓 𝑛 (𝑟 1). When the relative change is less than a
5.2. DVFS-integrated hybrid WOA-GWO scheduling model specified tolerance 𝜖𝑓 e.g., 𝜖𝑓 = 0.001 or 0.1%, the stop criterion
is met. This stop criterion is defined as:
The section before this one explains the task prioritization pro- 𝑓𝑓 𝑛 (𝑟) 𝑓𝑓 𝑛 (𝑟 1)
cess, where tasks are arranged in descending order of priorities by < 𝜖𝑓 (42)
𝑓𝑓 𝑛 (𝑟)
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Karishma and H. Kumar Computer Standards & Interfaces 97 (2026) 104106
Fig. 10. Inversion mutation operator.
ii If the above criterion is not satisfied, the optimization process Algorithm 1 Pseudo code for the insert-reversed block operation
halts after reaching the maximum number of iterations, set here ( )
|𝑋|
to 500. 1: temp = random 2, ;
2
2: arr positions [temp];
5.2.2. Scheduling fitness function 3: function replace(search_agent, i)
HWWO integrates metaheuristic techniques for tasks scheduling, 4: for j = 0 to temp - 1 do
with the effectiveness contingent upon the crafted fitness function 5: search_agent[j] = switch(i, positions[value - j - 1]);
determining suitable computing resources. Eq. (43) outlines the formu- 6: end for
lation of the fitness function for each particle in HWWO. 7: return search_agent;
[ |𝑌 | |𝑋|
( )] 8: end function
𝑀𝑆(𝐺) ∑ −𝜆𝑙,𝑚𝑎𝑥
𝑤̂ 𝑖,𝑙 𝑓𝑙,𝑚𝑎𝑥
𝑓𝑓 𝑛(𝜏𝑖 ,𝑌𝑙 ,𝑓𝑙, ) = 𝑚𝑖𝑛 𝜎1 𝑃𝑙,𝑠 + 𝜎2 𝑒 𝑓𝑙,
(43) 9: function insert_reversed_block_operation(assignment)
𝐷𝐿(𝐺)
𝑙=1 𝑖=1 10: matrix permutations[|𝑋| 1][|𝑋|];
Here, 𝜎1 and 𝜎2 signify the optimal weights for energy consumption 11: positions = sorted(random(0, |𝑋| - 1, temp)); ⊳ Select temp
and computation time, subject to 𝜎1 + 𝜎2 = 1. During selection, each number of positions of tasks.
solutions objectives receive random weights, encouraging exploration 12: permutations[0] = assignment;
in various directions. 13: for i = 0 to |𝑋| - 3 do
14: if i not in positions then
5.2.3. Inversion mutation 15: permutations[i + 1] = replace(permutations[i], i);
Inversion mutation [92], an operator in evolutionary algorithms, 16: end if
randomly selects a segment of genes within a chromosome and reverses 17: end for
their order. This process fosters genetic diversity by exploring different 18: end function
regions of the search space, potentially leading to improved solu-
tions. This can be understood by referring to the illustrative example
presented in Fig. 10.
formulating an effective HWWO approach for tackling optimization
challenges lies in the intricate process of developing an appropriate en-
5.2.4. Insert-reversed block operation
coding mechanism to model the constituent elements or search agents
Excessive mutation can disrupt previously found good solutions and
within the HWWO framework. For optimization scenarios involving |𝑌 |
impede the algorithms convergence toward optimal or near-optimal
processors, a viable strategy to model the constituent search particles
solutions. This occurs because random changes introduced by mutation
is through the utilization of |𝑌 |-dimensional coordinate vectors, as
may not always improve the solutions. Consequently, after applying the
illustrated in the subsequent representation.
inversion mutation operator, the insert-reversed block operation [93] is
integrated into the algorithm. This operation inserts a reversed block of → → → →
task permutation into all (|𝑋| 1) conceivable positions within a |𝑋|- 𝑋 = (𝑋 1 , 𝑋 2 , … , 𝑋 |𝑌 | )
dimensional search agent, as outlined in Algorithm 1 and illustrated in
Fig. 11. Step 2: Evaluating fitness values for each particle in assignment.
This step calculates the fitness score for each HWWO particle,
5.2.5. HWWO scheduling algorithm reflecting the task-to-processor assignment. The hybrid WOAGWO
The pseudocode in Algorithm 2 outlines the procedure for tasks framework evaluates individual particle fitness using the function de-
scheduling employing the HWWO technique. A more in-depth eluci- fined in Eq. (43). When a particles current fitness exceeds its previous
dation of these steps is presented in the following paragraphs: best, the global best fitness is updated to the new higher value.
Step 1: Whale-wolf encoding and position vector initialization.
Step 3: Updating the position vector.
The developed technique views tasks as elements within the HWWO
framework, which systematically refines their designated positions over The proposed HWWO approach updates the position of each whale
successive iterations, ultimately converging on an optimal task allo- using equations ((2), (8), (10)) under different scenarios, whereas
cation among the available processors. One of the key obstacles in Eq. (17) facilitates the positional update of the wolf for every iteration,
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Karishma and H. Kumar Computer Standards & Interfaces 97 (2026) 104106
Fig. 11. Example demonstrating the insert-reversed block operation.
→ → →
taking into consideration the values of 𝑍 𝛼 , 𝑍 𝛽 , and 𝑍 𝛿 as defined by assignment, carried out between lines 1921, has a time complexity
Eqs. (13)(16). of 𝑂(|𝑌 |). The iterative loop spanning steps 33 to 63 also requires a
time complexity scaling as 𝑂(|𝑌 | |𝑋|). As a result, the overall time
Step 4: Emergence of optimal scheduling. complexity per iteration of the HWWO algorithm is the cumulative sum
The algorithm models task assignment using whales and wolves. Ap- of these individual complexities, amounting to 𝑂(|𝑋| |𝑌 |) + 𝑂(|𝑌 |).
plying mutated and permutated HWWO, particle positions are adjusted To store the assignments of |𝑋| tasks across |𝑌 | processors, a matrix
for optimal tasks scheduling on processors. With optimal scheduling structure of size |𝑌 | |𝑋| is required, and an array of length |𝑌 | is
obtained, the EES algorithm then optimizes voltage and frequency needed to hold the fitness value of each assignment. Consequently,
distribution among all processors. the overall space complexity for representing and evaluating these
Step 5: Calculating total energy consumption, and reliability. assignments is 𝑂(|𝑋| |𝑌 |) + 𝑂(|𝑌 |).
The aggregate energy consumption of the resulting set of particles Alternatively, the algorithms based on energy considerations, such
can be determined by utilizing Eq. (25), while their reliability metric as ESRG, EPM, and REREC techniques, exhibit time complexities of
is ascertained through the application of Eq. (29). 𝑂(|𝑋|2 |𝑌 |), 𝑂(|𝑋|2 |𝑌 |3 ), and 𝑂(|𝑋|2 |𝑌 |), respectively. It is
The outlined steps should be iteratively executed until the stopping noteworthy that, in terms of time complexity, the proposed algorithm
criteria or termination condition is met. The following provides a surpasses the performance of the other existing algorithms in this
comprehensive description of Algorithm 2. domain.
Fig. 12 visually depicts the scheduling outcomes obtained with the
proposed HWWO algorithm, and Fig. 13 illustrates the flowchart of 6. Experimental evaluation
the proposed model. The algorithm effectively reduces total energy
consumption and enhances reliability. Using Eq. (25), the total energy This study aims to develop an approach that improves system
consumption 𝐸̂ 𝑡𝑜𝑡𝑎𝑙 (𝐺) is calculated as 75.673 units, with 𝐸̂ 𝑠 (𝐺) being reliability, reduces the overall computation time, and conserves energy
60.6 units and 𝐸̂ 𝑑 (𝐺) being 15.073 units. Furthermore, to satisfy the usage. The proposed models performance in handling tasks scheduling
reliability goal 𝑅𝑒(𝑔𝑜𝑎𝑙) (𝐺) i.e., 𝑅𝑒(𝑚𝑖𝑛) (𝐺) ≤ 𝑅𝑒(𝑔𝑜𝑎𝑙) (𝐺) ≤ 𝑅𝑒(𝑚𝑎𝑥) (𝐺), the across heterogeneous distributed systems has been rigorously evaluated
maximum reliability 𝑅𝑒(𝑚𝑎𝑥) (𝐺) and the minimum reliability 𝑅𝑒(𝑚𝑖𝑛) (𝐺) through a comprehensive set of experiments. This section outlines the
for the DAG are evaluated as 0.99989 and 0.89738 respectively. Here, simulations conducted and the evaluation metrics configured to address
the reliability goal, 𝑅𝑒(𝑔𝑜𝑎𝑙) (𝐺), is set at 0.95, and the obtained reliabil- the stated problem using the proposed algorithm. An in-depth analysis
ity, 𝑅𝑒 (𝐺), stands at 0.978526 > 𝑅𝑒(𝑔𝑜𝑎𝑙) (𝐺). The improvement is clear of each experiment is provided in the following subsections.
when contrasted with the energy consumption and reliability results
shown in Figs. 59, representing the HEFT, DECM, EPM, REREC, and 6.1. Experimental metrics
ESRG algorithms.
The results for the DAG, as depicted in Fig. 4, clearly highlight the The HWWO algorithms efficacy in distributed computing is com-
superiority of the proposed algorithm in reducing energy consumption prehensively evaluated using multiple performance metrics for an-
and enhancing system reliability. alytical assessment. These metrics cover total energy consumption,
system reliability, computation time, resource utilization, SLR, CCR,
5.2.6. Time and space complexities and sensitivity analysis. This comprehensive assessment aims to provide
The computational time complexities required by the WOA and the insights into the algorithms performance and its potential impact on
GWO expressed as 𝑂(|𝑋| |𝑌 |). In the proposed HWWO technique, the distributed computing environment.
the time taken for steps 1417, during which the mutation operation With regard to performance evaluation, the proposed algorithms
is performed on each assignment, exhibits an identical complexity of capabilities are benchmarked through two distinct stages. Firstly, a
𝑂(|𝑋| |𝑌 |). Moreover, the evaluation of the fitness function for each comparative analysis is conducted between the introduced HWWO
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Karishma and H. Kumar Computer Standards & Interfaces 97 (2026) 104106
Fig. 12. Best scheduling result of the DAG shown in Fig. 4 using proposed HWWO technique.
Fig. 13. Flowchart of the proposed HWWO model.
technique and several existing state-of-the-art methods, namely HEFT, is carried out across multiple scenarios, generated by varying the
DECM, EPM, REREC, and ESRG. Additionally, the successful state- number of tasks over different generations, to provide a comprehensive
of-the-art algorithms from the CEC2020 competition on real-world understanding of the algorithms performance under diverse conditions.
single objective constrained optimization specifically, SASS [94], The assessment of the presented benchmark suite is conducted on a
sCMAgES [95], EnMODE [96], and COLSHADE [97] are incorporated personal computer equipped with the Microsoft Windows 11 operating
as four benchmark algorithms for comparative evaluation in the con- system, featuring an INTEL Core i3 CPU and 8 GB of RAM.
text of real-world optimization challenges, as outlined in the relevant Stage I
literature [98]. Furthermore, the proposed methodology is evaluated
against several metaheuristic approaches, including PSO, GWO, ACO, 6.2. Benchmark analysis with state-of-the-art algorithms
KH, WOA, DA (dragonfly algorithm) [67], and AHA (artificial hum-
mingbird algorithm) [67], using various performance metrics. The The subsection delves into an assessment of the proposed algo-
algorithms capabilities are also assessed through a series of benchmark rithms effectiveness, drawing comparisons with state-of-the-art meth-
tests involving unimodal test functions, which are compared against the ods across various performance metrics. The evaluation encompasses
aforementioned metaheuristic techniques. This comparative analysis three distinct scenarios, wherein the validation process incorporates
FFT, GE, and constrained optimization challenges from the renowned
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Algorithm 2 The HWWO tasks scheduling algorithm
52: assignments[𝑖] = inversion_mutation(assignments[𝑖], 0.2);
Input:
53: assignments[𝑖] = insert_reversed_block_operation
Dataset 𝑊̂ 𝐶𝐸𝑇
No. of processors, |𝑌 | (assignments[𝑖]);
No. of tasks, |𝑋| 54: end( for )
𝑓𝑓 𝑛 (𝑟)𝑓𝑓 𝑛 (𝑟1)
Population size, |𝑌 | 55: if < 𝜖𝑓 (= 0.001) then
𝑓𝑓 𝑛 (𝑟)
Control coefficient, 𝜇
56: 𝑟 = (max_iteration);
Maximum no. of iterations, 𝑟
57: else
Output:
Global best solution (best tasks assignment) 58: 𝑟 = 𝑟 + 1;
Begin 59: end if
1: matrix assignments[|𝑌 |][|𝑋|] = randomly assign |𝑋| tasks in the 60: for 𝑖 = 0 to |𝑌 | 1 do
processors prioritizing on the basis of rank; 61: fitness[𝑖] = fitness(assignments[𝑖]);
2: tasks = order by (rank, decreasing); 62: end for
3: function fitness(assignment)[ ( )] 63: end while
𝑤̂ 𝑓
∑|𝑌 | ∑|𝑋| −𝜆𝑙,𝑚𝑎𝑥 𝑖,𝑙 𝑓𝑙,𝑙,𝑚𝑎𝑥 64: best_assignment = assignment with least fitness value;
4: 𝑓𝑓 𝑛(𝜏𝑖 ,𝑌𝑙 ,𝑓𝑙, ) = 𝑚𝑖𝑛 𝜎1 𝑙=1 𝑃𝑙,𝑠 𝑀𝑆(𝐺)
𝐷𝐿(𝐺)
+ 𝜎 2 𝑖=1
𝑒 ;
65: Implement the EES algorithm to optimize voltage and frequency
5: return 𝑓𝑓 𝑛(𝜏𝑖 ,𝑌𝑙 ,𝑓𝑙, ) ; distribution among all processors
6: end function
7: function inversion_mutation(assignment, mutation_rate)
8: if 𝑟𝑎𝑛𝑑𝑜𝑚(0, 1) < 𝑚𝑢𝑡𝑎𝑡𝑖𝑜𝑛_𝑟𝑎𝑡𝑒 then Table 6
9: 𝑖, 𝑗 = sorted(random(|𝑋|, 2)); Parameter setting for stage I.
10: assignment[𝑖: 𝑗 + 1] = assignment[𝑖: 𝑗 + 1][:: -1]; Parameter Values
11: end if
𝑤̂ 𝑖,𝑙 (𝑚𝑠) [10, 100]
12: return assignment; 𝑐̂𝑖,𝑘 (𝑚𝑠) [10, 100]
13: end function 𝑃𝑙,𝑠 [0.1, 0.5]
14: for 𝑖 = 0 to |𝑌 | 1 do 𝑃𝑙,𝑖𝑛𝑑 [0.03, 0.07]
15: assignments[𝑖] = random assignment to processors (tasks); 𝐶𝑙,𝑒𝑓 [0.8, 1.2]
16: assignments[𝑖] = inversion_mutation(assignments[𝑖], 0.2); 𝑚𝑙 [2.5, 3.0]
17: end for 𝑓𝑙,𝑚𝑎𝑥 1 GHz
18: arr fitness_values[𝑌 ]; 𝑙1 and 𝑙2 [0, 1]
19: for 𝑖 = 0 to |𝑌 | 1 do 𝜇 [0, 2]
𝜆𝑙,𝑚𝑎𝑥 [0.0003, 0.0009]
20: fitness_values[𝑖] = fitness(assignments[𝑖]);
𝐶𝐶𝑅 0.1, 0.5, 1, 5, 10
21: end for
22: 𝑍[0] = alpha assignment;
23: 𝑍[1] = beta assignment;
CEC2020 competition. Complementing these scenarios, a diverse array
24: 𝑍[3] = delta assignment;
→ → → of experiments centered around tasks scheduling in a multiprocess-
25: function wolf(𝑀 , 𝜇, 𝜉 , 𝜁 )
ing environment is conducted. The validation outcomes underscore
26: matrix wolf_particles[3][|𝑋|];
the algorithms efficacy. It is noteworthy that each algorithm un-
27: for 𝑖 = 0 to 2 do
→ → dergoes independent iterations, refining its functions in pursuit of
28: 𝛶 = | 𝜉 𝑍[𝑖] 𝑀 |;
→ → → optimal performance. The comprehensive evaluation aims to under-
29: 𝑤𝑜𝑙𝑓 _𝑝𝑎𝑟𝑡𝑖𝑐𝑙𝑒𝑠[𝑖] = 𝑍[𝑖] 𝜁 𝛶 ;
stand the algorithms capabilities in addressing real-world optimization
30: end for
and scheduling challenges. The validation of the algorithm is facili-
31: return 𝑤𝑜𝑙𝑓 _𝑝𝑎𝑟𝑡𝑖𝑐𝑙𝑒𝑠[0]+𝑤𝑜𝑙𝑓 _𝑝𝑎𝑟𝑡𝑖𝑐𝑙𝑒𝑠[1]+𝑤𝑜𝑙𝑓 _𝑝𝑎𝑟𝑡𝑖𝑐𝑙𝑒𝑠[2]
;
3 tated through simulations conducted within a replicated heterogeneous
32: end function
33: while 𝑟 < max_iteration do distributed embedded system environment, comprising 95 processors
( )
34: 2
𝜇 = 2 𝑟 𝑚𝑎𝑥_𝑖𝑡𝑒𝑟𝑎𝑡𝑖𝑜𝑛 ; capable of handling tasks of varying complexities. These processors
35: 𝑏 = random constant; exhibit diverse processing capabilities, with their specifications and
36: update best assignments on the basis of least fitness value; the corresponding application parameters closely mirroring the details
37: for 𝑖 = 0 to |𝑌 | 1 do outlined in Refs. [8,91]. The input data parameters employed in this
→ →
38: update 𝑟, 𝜁 , 𝜉 , 𝜈, p; stage are delineated in Table 6, wherein each frequency magnitude un-
39: if 𝑝 < 0.5 then dergoes discretization and is represented with a precision of 0.01 GHz.
→ →
40: 𝐷 = | 𝜉 𝑏𝑒𝑠𝑡_𝑎𝑠𝑠𝑖𝑔𝑛𝑚𝑒𝑛𝑡 𝑎𝑠𝑠𝑖𝑔𝑛𝑚𝑒𝑛𝑡𝑠[𝑖]|;
Following the simulations, a comprehensive evaluation is undertaken,
→ wherein various assessment metrics are computed, including the av-
41: if | 𝜁 | < 1 then
→ → erage execution time, as well as the standard deviation and mean
42: assignments[𝑖]=|𝑏𝑒𝑠𝑡_𝑎𝑠𝑠𝑖𝑔𝑛𝑚𝑒𝑛𝑡 𝜁 𝐷|; of solutions across the iterative process, as described in [98]. This
43: else
evaluation replicates real-world heterogeneous distributed embedded
44: 𝑗 = random(0, |𝑌 |);
→ → systems, providing insights into the algorithms performance.
45: 𝑎𝑠𝑠𝑖𝑔𝑛𝑚𝑒𝑛𝑡𝑠[𝑖] = 𝑎𝑠𝑠𝑖𝑔𝑛𝑚𝑒𝑛𝑡𝑠[𝑗] 𝜁 𝐷;
46: end if
47: else 6.2.1. Scenario 1
48: 𝐷 = |𝑏𝑒𝑠𝑡_𝑎𝑠𝑠𝑖𝑔𝑛𝑚𝑒𝑛𝑡 𝑎𝑠𝑠𝑖𝑔𝑛𝑚𝑒𝑛𝑡𝑠[𝑖]|; This scenario conducts a rigorous assessment of the efficacy of the
49: 𝑀 = 𝐷 𝑒𝑏𝜈 𝑐𝑜𝑠(2𝜋𝜈) + 𝑎𝑠𝑠𝑖𝑔𝑛𝑚𝑒𝑛𝑡𝑠[𝑖]; HWWO-based technique through an examination of 15 real-world op-
→ → →
50: assignments[𝑖] = wolf(𝑀 , 𝜇, 𝜁 , 𝜉 ); timization problems. The assessment utilizes four algorithms identified
51: end if in the CEC2020 competition on real-world single objective constrained
optimization, namely the SASS algorithm, the sCMAgES algorithm,
the EnMODE, and the COLSHADE algorithm. The article leverages
these algorithms to evaluate the performance of the HWWO-based
16
Karishma and H. Kumar Computer Standards & Interfaces 97 (2026) 104106
Table 7
15 real-world constrained optimization problems.
Problem Name D g h
𝐶𝑜𝑝𝑡1 Optimal power flow (minimization of active power loss) 126 0 116
𝐶𝑜𝑝𝑡2 Topology optimization 30 30 0
𝐶𝑜𝑝𝑡3 Process flow sheeting problem 3 3 0
𝐶𝑜𝑝𝑡4 Gas transmission compressor design (GTCD) 4 1 0
𝐶𝑜𝑝𝑡5 SOPWM for 3-level inverters 25 24 1
𝐶𝑜𝑝𝑡6 Optimal power flow (minimization of fuel cost) 126 0 116
𝐶𝑜𝑝𝑡7 Optimal power flow (minimization of active power loss and fuel cost) 126 0 116
𝐶𝑜𝑝𝑡8 SOPWM for 5-level inverters 25 24 1
𝐶𝑜𝑝𝑡9 Pressure vessel design 4 4 0
𝐶𝑜𝑝𝑡10 Optimal sizing of distributed generation for active power loss minimization 153 0 148
𝐶𝑜𝑝𝑡11 Wind farm layout problem 30 91 0
𝐶𝑜𝑝𝑡12 Microgrid power flow (islanded case) 76 0 76
𝐶𝑜𝑝𝑡13 Optimal setting of droop controller for minimization of active power loss in islanded microgrids 86 0 76
𝐶𝑜𝑝𝑡14 Microgrid power flow (grid-connected case) 74 0 74
𝐶𝑜𝑝𝑡15 Optimal setting of droop controller for minimization of reactive power loss in islanded microgrids 86 0 76
technique on the selected real-world optimization problems. The ar-
ticle presents a detailed description of the attributes that define the
real-world problems under investigation, including their dimensions
and the number of equality and inequality constraints involved. This
information is comprehensively outlined in Table 7. To ensure a fair
and consistent comparison, the parameters of the four algorithms are
maintained at their original settings as documented in the relevant
literature [9497]. To ensure an impartial evaluation, the proposed
algorithm is executed for 500 iterations, adhering to the guidelines
outlined in [98]. This ensures an equal number of function evaluations
across methods. Subsequently, a statistical analysis is conducted using
the Wilcoxon signed-rank test [99] to assess the HWWOs performance
relative to the other algorithms under consideration.
The simulation outcomes for 15 real-world challenges are show-
cased in Table 8, which provides comprehensive information regarding
the best fitness value, mean fitness value, worst fitness value, and the
standard deviation (St. Dev) of the fitness values.
The results displayed in Table 8 demonstrate the proficiency of the
HWWO algorithm in tackling the majority of these problems, exhibiting
commendable performance. Notably, some of the solutions obtained
Fig. 14. DAG of FFT application with 𝜌 = 4.
by HWWO surpass those achieved by competing algorithms. To facil-
itate a comprehensive comparison of algorithm performance on the
proposed benchmark suite, we have adopted the ranking methodology
outlined in the CEC2020 competition [98]. The evaluation process benchmarks (𝑝 < 0.05). These findings suggest that the HWWO algo-
assigns weighted scores to the best, mean, and median results obtained rithm provides faster convergence and improved accuracy in solving
from 25 independent runs of each algorithm to quantify their perfor- optimization problems, which could translate into better outcomes in
mance, as outlined in [98]. The weighted performance measures (PM) practical applications such as logistics and scheduling optimization.
are: HWWO (0.321089, rank 1), SASS (0.335719, rank 2), EnMODE
(0.351856, rank 3), sCMAgES (0.415387, rank 4), and COLSHADE 6.2.2. Scenario 2
(0.493992, rank 5). Outperforming the others, HWWO demonstrates its In this scenario, the proposed approach rigorously evaluates the
effectiveness in handling diverse real-world problems with acceptable effectiveness of the HWWO technique through an analysis of the FFT
performance. algorithm. The visual depiction, illustrated in Fig. 14, showcases a
parallel implementation of the FFT application [8,86], incorporating
The results of the Wilcoxon signed-rank test, presented in Table
a crucial parameter value of 𝜌 = 4. The parameter 𝜌 governs the
9, highlight the effectiveness of the proposed HWWO algorithm when
applications task count |𝑋| via |𝑋| = (2 𝜌 1) + 𝜌 𝑙𝑜𝑔2 (𝜌), and
compared to other methods. The table shows the ranks of the HWWO
is exponentially related to an integer 𝑦 through 𝜌 = 2𝑦 . As illustrated
algorithm relative to the second algorithm in terms of best fitness
in Fig. 14, the application achieves a task count of |𝑋| = 15, which
values, with 𝑇 + , 𝑇 , and 𝑇 indicating the statistical results. 𝑇 + repre-
occurs when 𝜌 is set to 4. The following are three experiments evaluated
sents the superiority of the HWWO algorithm. The p-values, calculated
utilizing the FFT application.
at a 5% significance level, test the null hypothesis that the median
difference between the algorithms is zero. Additionally, the final row of Experiment 1: This experimental work aims to conduct a comprehen-
Table 9 summarizes the counts of 𝑇 + and 𝑇 , as well as the test statistic, sive comparative evaluation of the proposed HWWO technique against
offering a clear overview of the results. The Wilcoxon signed-rank test is existing algorithms. The primary focus is to assess their respective
particularly suited for paired comparisons in situations where normality performances concerning total energy consumption and computational
cannot be assumed, making it a reliable tool for validating performance time requirements within the context of parallel applications involving
differences in real-world optimization problems. The results indicate FFT. This experimental study employs a rigorous deadline and reliabil-
significant improvements in the performance of the HWWO algorithm, ity constraints, expressed as 𝐷𝐿(𝐺) = 𝐿𝐵(𝐺) 1.4 and 𝑅𝑒(𝑔𝑜𝑎𝑙) (𝐺) =
with 𝑇 + accounting for 86.96% and 𝑇 for 13.03% of the evaluated 0.90 respectively, where the complexity of the parallel application is
17
Karishma and H. Kumar Computer Standards & Interfaces 97 (2026) 104106
Table 8
Results of 15 real-world constrained optimization problems.
Problem Performance Optimization Algorithm
metric SASS COLSHADE EnMODE sCMAgES HWWO
𝐶𝑜𝑝𝑡1 Best fitness 5.13E+4 7.08E+4 7.10E+4 7.12E+4 5.19E+4
Mean fitness 5.33E+4 7.08E+4 7.22E+4 7.22E+4 5.37E+4
Worst fitness 5.51E+4 7.08E+4 7.61E+4 7.71E+4 5.66E+4
St. Dev 1.07E+2 2.12E12 1.14E+2 2.14E+2 1.15E+2
𝐶𝑜𝑝𝑡2 Best fitness 3.06E+4 3.06E+4 3.06E+04 3.06E+04 3.05E+4
Mean fitness 3.06E+4 3.06E+4 3.08E+04 3.08E+04 3.06E+4
Worst fitness 3.06E+4 3.07E+4 3.08E+04 3.08E+04 3.06E+4
St. Dev 3.07E11 2.51E7 2.53E+1 2.51E+1 7.46E1
𝐶𝑜𝑝𝑡3 Best fitness 3.68E+04 3.67E+4 3.67E+4 3.67E+4 3.63E+4
Mean fitness 3.68E+04 3.69E+4 3.67E+4 3.67E+4 3.63E+4
Worst fitness 3.68E+04 3.69E+4 3.67E+4 3.67E+4 3.63E+4
St. Dev 1.69E15 7.51E+1 4.53E15 4.53E15 1.66E16
𝐶𝑜𝑝𝑡4 Best fitness 5.29E+05 5.46E+05 5.32E+05 5.45E+05 5.26E+05
Mean fitness 5.29E+05 5.46E+05 5.35E+05 5.45E+05 5.28E+05
Worst fitness 5.31E+05 5.48E+05 5.36E+05 5.48E+05 5.28E+05
St. Dev 7.13E4 2.36E4 1.66E+2 3.31E04 1.16E1
𝐶𝑜𝑝𝑡5 Best fitness 1.60E+6 1.67E+06 1.34E+06 1.34E+6 1.34E+06
Mean fitness 1.67E+6 1.67E+06 1.34E+06 1.38E+6 1.34E+06
Worst fitness 1.67E+6 1.67E+06 1.36E+06 1.38E+6 1.36E+06
St. Dev 2.06E+4 1.05E09 3.66E7 5.14E+2 3.66E7
𝐶𝑜𝑝𝑡6 Best fitness 6.85E+07 6.91E+7 6.85E+07 6.85E+07 6.85E+07
Mean fitness 6.87E+07 6.91E+7 6.87E+07 6.89E+07 6.87E+07
Worst fitness 6.89E+07 6.93E+7 6.89E+07 6.89E+07 6.89E+07
St. Dev 2.27E+04 6.61E04 2.27E+04 5.42E+04 2.27E+04
𝐶𝑜𝑝𝑡7 Best fitness 5.73E+6 5.76E+6 5.73E+6 5.77E+6 5.76E+6
Mean fitness 5.74E+6 5.79E+6 5.74E+6 5.79E+6 5.77E+6
Worst fitness 5.76E+6 5.79E+6 5.76E+6 5.79E+6 5.77E+6
St. Dev 1.05E+4 6.05E+4 1.05E+4 3.08E+4 5.05E+3
𝐶𝑜𝑝𝑡8 Best fitness 9.93E4 9.97E04 8.92E4 8.92E4 8.92E4
Mean fitness 9.95E4 9.97E04 8.92E4 8.92E4 8.95E4
Worst fitness 9.96E4 9.97E04 8.96E4 8.93E4 8.95E4
St. Dev 4.34E6 5.41E06 6.63E4 4.31E6 4.31E6
𝐶𝑜𝑝𝑡9 Best fitness 1.89E+2 4.08E+03 4.08E+03 4.18E+03 1.89E+2
Mean fitness 1.91E+2 4.25E+03 4.31E+03 4.26E+03 1.91E+2
Worst fitness 1.99E+2 4.37E+03 4.37E+03 4.31E+03 1.99E+2
St. Dev 2.80E1 8.85E+01 5.85E+01 1.55E+01 2.80E1
𝐶𝑜𝑝𝑡10 Best fitness 6.16E02 6.74E02 6.26E02 3.26E02 3.26E02
Mean fitness 6.96E02 7.85E02 7.59E02 6.96E02 6.96E02
Worst fitness 7.92E02 9.04E02 9.23E02 7.32E02 7.32E02
St. Dev 5.28E02 5.26E02 4.49E05 4.28E05 4.28E05
𝐶𝑜𝑝𝑡11 Best fitness 3.06E+4 3.06E+4 3.11E+4 3.02E+4 2.94E+4
Mean fitness 3.08E+4 3.09E+4 3.11E+4 3.07E+4 2.94E+4
Worst fitness 3.11E+4 3.13E+4 3.13E+4 3.07E+4 2.94E+4
St. Dev 7.12E+1 2.61E+1 4.64E4 4.64E+1 0
𝐶𝑜𝑝𝑡12 Best fitness 1.67E+1 1.67E+1 1.68E+1 1.72E+1 1.70E+1
Mean fitness 1.67E+1 1.68E+1 1.68E+1 1.74E+1 1.73E+1
Worst fitness 1.69E+1 1.69E+1 1.71E+1 1.74E+1 1.73E+1
St. Dev 2.03E1 2.03E1 3.08E1 4.13E+1 2.03E1
𝐶𝑜𝑝𝑡13 Best fitness 5.75E+2 5.71E+2 5.24E+2 5.57E+2 5.24E+2
Mean fitness 5.78E+2 5.79E+2 5.29E+2 5.59E+2 5.29E+2
Worst fitness 5.79E+2 5.79E+2 5.33E+2 5.61E+2 5.33E+2
St. Dev 2.51E+1 4.43E+1 1.61E+1 7.01E+1 1.61E+1
𝐶𝑜𝑝𝑡14 Best fitness 3.55E+2 3.62E+2 3.60E+2 3.55E+2 3.53E+2
Mean fitness 3.74E+2 3.78E+2 4.45E+2 3.61E+2 3.61E+2
Worst fitness 3.79E+2 3.79E+2 4.71E+2 3.66E+2 3.63E+2
St. Dev 8.01E+2 4.23E+2 7.32E+2 3.39E+1 3.37E+1
𝐶𝑜𝑝𝑡15 Best fitness 1.93E+5 1.89E+5 1.91E+5 1.89E+5 1.89E+5
Mean fitness 1.95E+5 1.91E+5 1.96E+5 1.89E+5 1.92E+5
Worst fitness 1.99E+5 1.97E+5 1.96E+5 1.89E+5 1.97E+5
St. Dev 1.32E+3 4.15E+3 5.80E+1 2.97E11 3.35E+1
intrinsically linked to the quantity of constituent tasks it comprises. The the HWWO algorithm in comparison to other existing algorithms. As
study deliberately varies |𝑋| from 95 (smaller scenarios) to 2559 (larger the task count rises, both the DECM and REREC algorithms yield
scenarios), while concurrently investigating the effects of 𝜌 ranging comparable performance levels. Notably, up to a task value of 511, the
from 16 to 256. ESRG algorithm stands out for its lower energy consumption compared
to EPM. Beyond this threshold, EPM gradually refines its outcomes,
Tables 10 and 11 present the outcomes from using FFT applications
albeit at the expense of higher energy usage in contrast to DECM
with varying 𝜌 values. In all experiments, HEFT (without DVFS tech-
and REREC. The best outcomes, highlighted in bold text, are further
nique) consistently consumes more energy. In Table 10, the parameter
illustrated in Fig. 15, which visually represents the data from Table 10,
|𝑋| demonstrates a spectrum of values ranging from 95 to 2559. This
offering a comprehensive comparative analysis.
underscores the superior energy consumption outcomes achieved by
18
Karishma and H. Kumar Computer Standards & Interfaces 97 (2026) 104106
Table 9
Results of Wilcoxon signed-rank test of Table 8.
Problem HWWO vs SASS HWWO vs COLSHADE HWWO vs EnMODE HWWO vs sCMAgES
Rank Rank Rank Rank
𝐶𝑜𝑝𝑡1 7 4 3 4
𝐶𝑜𝑝𝑡2 2 1 1 1.5
𝐶𝑜𝑝𝑡3 6 10 9 9
𝐶𝑜𝑝𝑡4 4.5 5 10 3
𝐶𝑜𝑝𝑡5 10 7
𝐶𝑜𝑝𝑡6 12
𝐶𝑜𝑝𝑡7 4.5 6.5 1.5
𝐶𝑜𝑝𝑡8 1 2
𝐶𝑜𝑝𝑡9 9 8 8
𝐶𝑜𝑝𝑡10 3 8 6.5
𝐶𝑜𝑝𝑡11 8 3 2 10
𝐶𝑜𝑝𝑡12 11 6 4.5 5.5
𝐶𝑜𝑝𝑡13 13 11 7
𝐶𝑜𝑝𝑡14 9 13 11 5.5
𝐶𝑜𝑝𝑡15 12 4.5
p-value 0.0116 0.0452 0.0370 0.0352
𝑇 + = Sum of positive number ranks 68.5 85 55 55
𝑇 = Sum of negative number ranks 22.5 6 11 0
𝑇 = min(𝑇 + , 𝑇 ) 22.5 6 11 0
Table 10
Energy consumption analysis for FFT parallel applications across task configurations.
|𝑋| Performance Algorithm
metric HEFT DECM EPM REREC ESRG HWWO
95 Best 1.48E+4 2.73E+3 6.83E+3 3.07E+3 6.81E+3 1.68E+3
Mean 1.53E+4 2.80E+3 6.90E+3 3.26E+3 6.89E+3 1.72E+3
Worst 1.58E+4 2.83E+3 6.94E+3 3.33E+3 6.94E+3 1.83E+3
St. Dev 3.17E+3 5.78E+1 7.31E+1 4.13E+1 7.23E+1 3.14E+1
223 Best 2.53E+4 7.13E+3 8.43E+3 7.44E+3 8.39E+3 4.11E+3
Mean 2.61E+4 7.21E+3 8.47E+3 7.49E+3 8.47E+3 4.18E+3
Worst 2.67E+4 7.33E+3 8.56E+3 7.57E+3 8.54E+3 4.23E+3
St. Dev 6.20E+1 1.28E+1 6.16E+1 2.69E+2 3.80E+3 1.02E+1
511 Best 3.64E+4 1.32E+4 2.18E+4 1.27E+4 2.06E+4 6.58E+3
Mean 3.72E+4 1.32E+4 2.27E+4 1.35E+4 2.17E+4 6.61E+3
Worst 3.72E+4 1.32E+4 2.37E+4 1.46E+4 2.29E+4 6.77E+3
St. Dev 1.28E+1 3.47E7 5.34E+1 7.28E+2 4.21E+2 5.54E+1
1151 Best 7.34E+4 3.26E+4 4.73E+4 3.26E+4 4.79E+4 9.75E+3
Mean 7.41E+4 3.35E+4 4.81E+4 3.37E+4 4.88E+4 9.79E+3
Worst 7.49E+4 3.43E+4 4.83E+4 3.43E+4 4.97E+4 9.79E+3
St. Dev 4.13E+4 2.13E+1 7.34E+2 5.81E+3 7.03E+2 2.34E+1
2559 Best 9.35E+4 6.17E+4 6.44E+4 6.21E+4 6.71E+4 4.73E+4
Mean 9.43E+4 6.28E+4 6.51E+4 6.37E+4 6.82E+4 4.86E+4
Worst 9.51E+4 6.39E+4 6.59E+4 6.47E+4 6.88E+4 4.93E+4
St. Dev 5.82E+4 3.72E+2 1.80E+2 4.63E+2 1.80E+2 7.37E+2
Within Table 11, it is notable that the EPM algorithm requires the specified reliability goals compared to other existing methods.
significantly more 𝐶𝑇𝑇 𝐴 . However, as the number of tasks increases, Contrastingly, the HEFT, EPM, and ESRG algorithms exhibit an inability
ESRG surpasses the other three algorithms in producing higher energy to fulfill the reliability constraints in the majority of scenarios. As
values. The 𝐶𝑇𝑇 𝐴 of the newly proposed HWWO algorithm is projected the reliability objective escalates from 0.91 to 0.95, HEFT, EPM, and
to occupy between 31.20% and 35.61% of the computational time ESRG manage to comply with the requirements, but struggle beyond
required by the DECM and REREC algorithms. Regarding performance that range. Conversely, DECM, REREC, and HWWO successfully meet
metrics, across a spectrum of values for |𝑋| from 95 to 2559, the 𝐶𝑇𝑇 𝐴 the reliability constraint within the range of 0.91 to 0.98, although
of the HWWO closely mirrors that of the DECM algorithm, consistently none of the algorithms can fulfill the rigorous 0.99 requirement. It
surpassing it. is noteworthy that if the upper bound for the reliability objective is
established at an excessively elevated level, the maximum attainable
Experiment 2: The study evaluates the reliability metrics and total reliability values for partial tasks may fall short of this upper bound in
energy consumption of an extensive FFT application under varying practical implementation scenarios.
reliability constraints. The experimental configuration involves 1151 Data presented in Table 12 has been shown graphically in Fig. 17.
tasks, with 𝜌 = 128. Additionally, the reliability goal, 𝑅𝑒(𝑔𝑜𝑎𝑙) (𝐺), is The table evaluates the energy consumption profiles of FFT applications
systematically varied from 0.91 to 0.99 in increments of 0.01, enabling when subjected to varying reliability criteria. For reliability thresholds
an assessment of the corresponding effects on reliability performance up to 0.98, the techniques DECM, REREC, and HWWO exhibit superior
and energy utilization. energy consumption performance in comparison to HEFT, EPM, and
The graphical representation in Fig. 16 illustrates the actual relia- ESRG. The algorithms HEFT, EPM, and ESRG are capable of producing
bility values attained by the large-scale FFT application when subjected energy outcomes only up to a reliability criterion of 0.95, as they fail
to varying reliability criteria. Among the techniques evaluated, the to meet the reliability constraints beyond this point, as evidenced by
HWWO algorithm demonstrates superior performance in accomplishing the findings illustrated in Fig. 16. Until the 0.98 reliability threshold,
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Karishma and H. Kumar Computer Standards & Interfaces 97 (2026) 104106
Fig. 15. Graphical representation of Table 10.
Table 11
𝐶𝑇𝑇 𝐴 values of FFT applications across diverse task quantities.
|𝑋| Performance Algorithm
metric DECM EPM REREC ESRG HWWO
95 Best 1.5E+1 2.57E+2 1.9E+1 2.31E+2 1.2E+1
Mean 2.62E+1 2.73E+2 2.6E+1 2.66E+2 2.2E+1
Worst 2.80E+1 3.27E+2 2.91E+1 3.25E+2 2.6E+1
St. Dev 3.15E+1 1.19E+2 5.4E+1 2.4E+2 4.8E+0
223 Best 2.1E+1 5.04E+2 3.9E+1 4.6E+2 2.1E+1
Mean 2.7E+1 5.73E+2 4.3E+1 4.8E+2 2.7E+1
Worst 3.8E+1 5.91E+2 4.3E+1 5.3E+2 3.1E+1
St. Dev 3.42E1 4.21E+2 2.06E+0 3.07E+2 3.42E+0
511 Best 5.6E+1 3.5E+3 6.3E+1 3.2E+3 4.7E+1
Mean 5.81E+1 3.6E+3 6.8E+1 3.4E+3 4.7E+1
Worst 6.04E+1 3.6E+3 7.3E+1 3.5E+3 4.92E+1
St. Dev 3.66E+1 3.01E1 7.2E+1 6.7E+0 8.9E1
1151 Best 2.62E+2 4.16E+3 3.31E+2 4.73E+3 2.49E+2
Mean 2.74E+2 4.16E+3 3.31E+2 4.73E+3 2.51E+2
Worst 2.74E+2 4.47E+3 3.47E+2 4.73E+3 2.51E+2
St. Dev 3.31E1 1.71E+3 1.08E1 3.26E1 3.31E1
2559 Best 4.7E+2 8.33E+3 5.4E+2 8.72E+3 3.48E+2
Mean 4.8E+2 8.42E+3 5.6E+2 8.74E+3 3.71E+2
Worst 4.8E+2 8.46E+3 5.6E+2 8.83E+3 3.71E+2
St. Dev 1.07E+1 3.72E+1 1.07E+1 6.01E+2 7.06E+2
DECM, REREC, and HWWO successfully fulfill the reliability constraints larger-scale scenarios), while simultaneously exploring the impacts of
in the majority of scenarios. Notably, among these three techniques, 𝜌 ranging from 16 to 256.
the HWWO algorithm demonstrates more favorable results by further The scheduling length ratio (SLR) is a widely adopted metric em-
optimizing energy consumption through an expanded exploration of ployed for evaluating and contrasting various scheduling algorithms. It
processor and frequency combination possibilities. HWWO surpasses is quantified as the ratio of the makespan to the cumulative sum of the
DECM and REREC in energy savings, reducing consumption by 33% minimum execution times of all tasks residing on the critical path of the
and 36% on average, correspondingly. However, it is pertinent to note DAG [86]. This can be expressed through the following mathematical
that none of the algorithms evaluated can achieve the stringent 0.99 formulation:
reliability requirement. 𝑀𝑆(𝐺)
𝑆𝐿𝑅 = ∑ (44)
𝜏𝑖 ∈𝐶𝑃𝑀𝐼𝑁 𝑚𝑖𝑛𝑌𝑙 ∈𝑌 (𝑤
̂ 𝑖,𝑙 )
Experiment 3: The current experiment examines the SLR and CCR
metrics for a comprehensive FFT application, considering variations The data presented in Table 13 and visually represented in Fig.
in 𝜌. This experimental approach incorporates a stringent deadline 18 demonstrates the average performance of various tasks scheduling
requirement, expressed as 𝐷𝐿(𝐺) = 𝐿𝐵(𝐺) 1.4, where the com- algorithms in terms of the SLR metric. The proposed HWWO algorithm
plexity of the parallel application is inherently tied to the number of exhibited the lowest SLR values across all experiments, outperforming
constituent tasks it encompasses. The study systematically alters |𝑋| the other techniques evaluated. Concerning SLR, HWWO established
from 95 (representing smaller-scale scenarios) to 2559 (representing itself as the superior approach. Across all task sizes, the HEFT algorithm
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Karishma and H. Kumar Computer Standards & Interfaces 97 (2026) 104106
Fig. 16. Graphical representation of actual reliability values under varying reliability constraints (in case of FFT).
Table 12
Energy consumption assessment for FFT applications with varying reliability criteria.
Reliability Performance Algorithm
goal metric HEFT DECM EPM REREC ESRG HWWO
0.91 Best 4.44E+4 2.36E+4 3.73E+4 2.46E+4 3.53E+4 1.25E+4
Mean 4.51E+4 2.45E+4 3.81E+4 2.47E+4 3.71E+4 1.29E+4
Worst 4.58E+4 2.47E+4 3.83E+4 2.53E+4 3.83E+4 1.32E+4
St. Dev 4.23E+1 4.13E2 5.24E+2 5.81E2 6.34E+2 5.24E4
0.92 Best 4.74E+4 2.43E+4 3.89E+4 2.54E+4 3.83E+4 1.71E+4
Mean 4.81E+4 2.47E+4 3.91E+4 2.54E+4 3.86E+4 1.78E+4
Worst 4.92E+4 2.47E+4 3.91E+4 2.54E+4 3.86E+4 1.78E+4
St. Dev 7.32E+4 6.28E11 7.04E4 6.28E11 5.34E4 4.02E7
0.93 Best 5.64E+4 3.71E+4 4.28E+4 3.71E+4 4.06E+4 2.71E+4
Mean 5.72E+4 3.78E+4 4.33E+4 3.85E+4 4.37E+4 2.88E+4
Worst 5.82E+4 3.88E+4 4.47E+4 3.92E+4 4.49E+4 2.94E+4
St. Dev 3.28E+4 7.12E+4 2.02E+4 5.08E+4 2.02E+4 2.02E+4
0.94 Best 6.74E+4 3.87E+4 4.89E+4 3.81E+4 4.82E+4 2.87E+4
Mean 6.74E+4 3.93E+4 4.93E+4 3.95E+4 4.89E+4 2.97E+4
Worst 6.74E+4 3.99E+4 4.97E+4 3.99E+4 4.97E+4 2.99E+4
St. Dev 3.28E+4 1.12E+4 7.02E+4 1.12E+4 5.52E+4 6.42E+4
0.95 Best 8.45E+4 6.17E+4 6.84E+4 6.37E+4 6.71E+4 4.24E+4
Mean 8.48E+4 6.28E+4 6.88E+4 6.37E+4 6.82E+4 4.46E+4
Worst 8.51E+4 6.39E+4 6.95E+4 6.37E+4 6.88E+4 4.53E+4
St. Dev 5.82E+4 3.72E+2 1.80E+4 4.63E8 8.75E+4 7.37E+4
0.96 Best 6.66E+4 6.71E+4 4.51E+4
Mean 6.78E+4 6.87E+4 4.51E+4
Worst 6.78E+4 6.91E+4 4.63E+4
St. Dev 3.72E+4 4.63E4 1.17E7
0.97 Best 7.05E+4 7.21E+4 6.19E+4
Mean 7.08E+4 7.21E+4 6.19E+4
Worst 7.09E+4 7.21E+4 6.19E+4
St. Dev 3.13E+3 3.33E11 3.33E11
0.98 Best 8.29E+4 8.41E+4 7.39E+4
Mean 8.31E+4 8.48E+4 7.57E+4
Worst 8.34E+4 8.48E+4 7.61E+4
St. Dev 6.37E+2 1.17E+2 4.52E+3
0.99 Best
Mean
Worst
St. Dev
consistently generated the poorest schedules, trailing behind EPM and size. The average SLR performance of HWWO across all generated
ESRG. Initially, EPM underperformed compared to ESRG, but as the graphs exceeded that of the DECM algorithm by 15% and the REREC
number of tasks increased, its performance surpassed that of ESRG. algorithm by 20.98%.
Notably, in scenarios where every path within the DAG constituted a
The communication to computation ratio (CCR) is a metric that
critical path, the DECM and REREC algorithms achieved comparable
quantifies the relative significance of communication overhead by di-
and superior results to HEFT, EPM, and ESRG, regardless of the input
viding the cumulative communication times across all edges by the
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Karishma and H. Kumar Computer Standards & Interfaces 97 (2026) 104106
Table 13
Average SLR for all algorithms with respect to various tasks (in case of FFT).
|𝑋| Average SLR
HEFT DECM EPM REREC ESRG HWWO
95 5.1E+1 3.4E+1 4.2E+1 3.7E+1 4.0E+1 2.4E+1
223 6.2E+1 4.6E+1 4.9E+1 4.6E+1 4.9E+1 3.8E+1
511 8.8E+1 5.2E+1 6.5E+1 5.8E+1 6.2E+1 4.7E+1
1151 1.1E+2 7.8E+1 8.8E+1 8.5E+1 9.2E+1 6.9E+1
2559 1.3E+2 8.3E+1 9.2E+1 8.9E+1 9.6E+1 7.6E+1
Fig. 17. Graphical representation of Table 12.
Fig. 18. Graphical representation of Table 13.
total execution times across all nodes in a DAG. Fig. 19 illustrates the DECM and REREC are comparable across different CCR values. How-
average SLR performance of various algorithms as a function of the ever, HWWO emerged as the top-performing algorithm, yielding the
CCR. When considering CCR values, HEFT consistently exhibited the best SLR outcomes for all CCR values considered. Notably, the average
poorest SLR results, surpassed by both EPM and ESRG, while DECM, SLR performance of HWWO across all generated graphs surpassed that
REREC, and HWWO demonstrated their ability to generate superior of DECM by 14.16% and REREC by 19.91%.
schedules compared to these algorithms. The schedules produced by
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Karishma and H. Kumar Computer Standards & Interfaces 97 (2026) 104106
Fig. 19. Graphical representation of SLR values with respect to CCR (in case of FFT).
6.2.3. Scenario 3
To rigorously assess the proposed techniques effectiveness, the
study conducts a comprehensive evaluation of the HWWO algorithms
performance through an analysis of the gaussian elimination (GE)
problem. The visual representation in Fig. 20 depicts a parallel im-
plementation of the GE application, incorporating a critical parameter
value of 𝜌 = 5, as described in [8,86]. Notably, the total number of
tasks, denoted as |𝑋|, is dynamically determined by the expression
2
|𝑋| = 𝜌 +𝜌2
2
. Specifically, when 𝜌 = 5, the resulting task count is
|𝑋| = 14, as illustrated in Fig. 20. This scenario highlights the intricate
interplay between the parameters 𝜌 and |𝑋| in the context of parallel
computing applications. The following three experiments are conducted
to evaluate the performance of the proposed approach using the GE
application as a benchmark.
Experiment 4: The overarching goal of this experimental endeavor is to
conduct a meticulous comparative assessment of the proposed HWWO
technique against existing algorithms. The primary goal is placed on
evaluating their respective performances concerning total energy con-
sumption and computational time requirements within the realm of
parallel applications involving GE. Underpinning this experimental
study is a stringent deadline and reliability constraints, formulated
as 𝐷𝐿(𝐺) = 𝐿𝐵(𝐺) 1.4 and 𝑅𝑒(𝑔𝑜𝑎𝑙) (𝐺) = 0.90 respectively, where
the complexity of the parallel application is intrinsically linked to the
quantity of constituent tasks it comprises. To comprehensively analyze
the techniques behavior, the study methodically varies the task count Fig. 20. DAG of GE application with 𝜌 = 5.
|𝑋| over a substantial range, spanning from 90 tasks (representing
smaller-scale scenarios) to 2555 tasks (larger-scale scenarios), while
concurrently investigating the effects of 𝜌 ranging from 13 to 71. in Fig. 21, providing a visual comparative analysis of the data from
Table 14.
Tables 14 and 15 present the outcomes from using GE applications
with varying 𝜌 values. In all experiments, HEFT (without DVFS tech-
nique) consistently consumes more energy. Table 14 shows that the
parameter |𝑋| has a wide range of values from 90 to 2555. This high- Table 15 shows that the EPM algorithm requires significantly higher
lights the superior energy efficiency of the HWWO algorithm compared 𝐶𝑇𝑇 𝐴 . However, as the number of tasks increases, ESRG outperforms
to other existing algorithms. As the number of tasks increases, both the other three algorithms in terms of higher energy values. The
the DECM and REREC algorithms exhibit similar performance levels. proposed HWWO algorithms 𝐶𝑇𝑇 𝐴 is projected to be 33.4% to 37.39%
Notably, the ESRG algorithm outperforms EPM in terms of lower energy of the computational time required by DECM and REREC algorithms.
consumption up to 495 tasks. Beyond that, EPM gradually improves its In terms of performance metrics, for |𝑋| values ranging from 90 to
results but at the cost of higher energy usage compared to DECM and 2555, the HWWO algorithms 𝐶𝑇𝑇 𝐴 closely follows and consistently
REREC. The best outcomes, highlighted in bold, are further illustrated outperforms the DECM algorithm.
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Karishma and H. Kumar Computer Standards & Interfaces 97 (2026) 104106
Table 14
Energy consumption analysis for GE parallel applications across task configurations.
|𝑋| Performance Algorithm
metric HEFT DECM EPM REREC ESRG HWWO
90 Best 3.18E+4 3.36E+3 7.88E+3 3.77E+3 7.81E+3 2.78E+3
Mean 3.33E+4 3.43E+3 7.94E+3 3.86E+3 7.89E+3 2.81E+3
Worst 3.38E+4 3.43E+3 7.94E+3 3.93E+3 7.94E+3 2.88E+3
St. Dev 5.04E+1 1.42E+0 3.31E+1 4.13E+1 2.13E+1 5.07E+1
230 Best 4.73E+4 7.93E+3 8.63E+3 7.93E+3 8.49E+3 4.71E+3
Mean 4.81E+4 7.93E+3 8.77E+3 7.93E+3 8.53E+3 4.79E+3
Worst 4.81E+4 7.93E+3 8.78E+3 7.93E+3 8.59E+3 4.83E+3
St. Dev 6.20E+4 2.32E7 3.26E+1 2.32E7 3.80E+1 2.32E+1
495 Best 6.27E+4 2.62E+4 3.08E+4 2.67E+4 3.05E+4 9.68E+3
Mean 6.27E+4 2.62E+4 3.16E+4 2.73E+4 3.11E+4 9.68E+3
Worst 6.27E+4 2.62E+4 3.16E+4 2.83E+4 3.16E+4 9.72E+3
St. Dev 8.08E4 3.47E7 2.34E+2 1.28E+3 4.44E+1 5.54E3
1127 Best 9.44E+4 6.05E+4 7.03E+4 6.35E+4 7.59E+4 4.25E+4
Mean 9.44E+4 6.05E+4 7.13E+4 6.35E+4 7.62E+4 4.25E+4
Worst 9.49E+4 6.11E+4 7.13E+4 6.41E+4 7.67E+4 4.25E+4
St. Dev 1.13E+2 1.25E+4 2.14E+4 1.15E+4 5.03E+4 7.34E9
2555 Best 9.75E+4 7.65E+4 9.44E+4 7.97E+4 9.54E+4 7.13E+4
Mean 9.82E+4 7.67E+4 9.51E+4 7.97E+4 9.54E+4 7.17E+4
Worst 9.88E+4 7.67E+4 9.59E+4 7.97E+4 9.59E+4 7.17E+4
St. Dev 1.02E+3 2.37E1 4.80E+4 5.87E7 3.80E+1 2.37E+2
Fig. 21. Graphical representation of Table 14.
reliability constraint from 0.91 to 0.98, but none of the algorithms can
meet the stringent 0.99 requirement.
Experiment 5: This experiment evaluates the reliability metrics and
total energy consumption of an extensive GE application under varying Fig. 23 visually represents the data from Table 16, showing the
reliability constraints. The experimental configuration involves 1127 energy consumption of GE applications under different reliability con-
tasks, with 𝜌 = 47. Additionally, the reliability goal, 𝑅𝑒(𝑔𝑜𝑎𝑙) (𝐺), is straints. Up to 0.98 reliability, DECM, REREC, and HWWO are more
systematically varied from 0.91 to 0.99 in increments of 0.01, enabling energy-efficient than HEFT, EPM, and ESRG. While HEFT, EPM, and
an assessment of the corresponding effects on reliability performance ESRG fail to meet reliability constraints beyond 0.95, as evident from
and energy utilization. Fig. 22, DECM, REREC, and HWWO successfully fulfill the reliability
The graphical representation in Fig. 22 illustrates the actual reliabil- requirements up to 0.98 in most cases. Among them, HWWO achieves
ity values attained by the GE application when subjected to varying reli- better energy savings by exploring more processor and frequency com-
ability criteria. Among the techniques evaluated, the HWWO algorithm binations, reducing consumption by 33% and 37% compared to DECM
demonstrates superior performance in accomplishing the specified reli- and REREC, respectively. However, none of the algorithms meet the
ability goals compared to other existing methods. In contrast, the HEFT, stringent 0.99 reliability requirement.
EPM, and ESRG algorithms struggle to meet the reliability constraints
in most scenarios. While they can comply when 𝑅𝑒(𝑔𝑜𝑎𝑙) (𝐺) is between Experiment 6: The current experiment examines the SLR and CCR
0.91 and 0.95, their performance deteriorates beyond that range. On metrics for a comprehensive GE application, considering variations
the other hand, DECM, REREC, and HWWO successfully satisfy the in 𝜌. This experimental approach incorporates a stringent deadline
24
Karishma and H. Kumar Computer Standards & Interfaces 97 (2026) 104106
Table 15
𝐶𝑇𝑇 𝐴 values of GE applications across diverse task quantities.
|𝑋| Performance Algorithm
metric DECM EPM REREC ESRG HWWO
90 Best 3.5E+1 4.31E+2 3.5E+1 3.81E+2 2.6E+1
Mean 3.6E+1 4.43E+2 3.6E+1 3.91E+2 2.6E+1
Worst 3.8E+1 4.43E+2 3.8E+1 3.95E+2 2.6E+1
St. Dev 7.5E1 5.6E+0 7.5E1 5.8E+0 0
230 Best 5.1E+1 7.14E+2 5.1E+1 6.84E+2 3.9E+1
Mean 5.9E+1 7.23E+2 6.7E+1 6.93E+2 4.4E+1
Worst 6.8E+1 7.41E+2 6.7E+1 6.94E+2 4.9E+1
St. Dev 6.4E+0 1.21E+2 7.4E+0 3.20E1 4.02E1
495 Best 6.4E+1 9.5E+3 7.1E+1 8.5E+3 6.4E+1
Mean 6.9E+1 1.6E+4 8.3E+1 1.3E+4 6.9E+1
Worst 7.2E+1 2.2E+4 9.2E+1 2.7E+4 7.2E+1
St. Dev 3.3E+0 5.10E+3 8.3E+1 2.09E+2 3.3E+0
1127 Best 7.7E+2 8.19E+3 7.9E+2 8.73E+3 7.49E+2
Mean 7.88E+2 8.25E+3 8.15E+2 8.83E+3 7.67E+2
Worst 7.94E+2 8.37E+3 8.7E+2 8.87E+3 7.77E+2
St. Dev 4.31E+1 2.71E+3 7.08E+1 5.08E+0 1.1E+1
2555 Best 8.57E+2 9.03E+3 8.77E+2 9.12E+3 8.57E+2
Mean 8.61E+2 9.22E+3 8.81E+2 9.28E+3 8.61E+2
Worst 8.69E+2 9.36E+3 8.91E+2 9.39E+3 8.69E+2
St. Dev 4.9E2 3.32E+1 6.07E+1 6.17E+1 4.9E+1
Fig. 22. Graphical representation of actual reliability values under varying reliability constraints (in case of GE).
constraint, formulated as 𝐷𝐿(𝐺) = 𝐿𝐵(𝐺) 1.4, where the com- results, while DECM, REREC, and HWWO generated superior schedules
plexity of the parallel application is inherently tied to the number of compared to HEFT, EPM, and ESRG. DECM and REREC produced com-
constituent tasks it encompasses. The study systematically alters |𝑋| parable schedules across different CCR values. However, HWWO out-
from 90 (representing smaller-scale scenarios) to 2555 (representing performed all others, yielding the best SLR outcomes for all considered
larger-scale scenarios), while simultaneously exploring the impacts of CCR values.
𝜌 ranging from 13 to 71.
Stage II
Table 17 and Fig. 24 demonstrate the average SLR performance
of various tasks scheduling algorithms. The proposed HWWO algo- 6.3. Benchmark analysis with metaheuristic algorithms
rithm exhibited the lowest SLR values, outperforming others. HWWO
emerged as the superior approach in terms of SLR. Across all task sizes,
In this stage the proposed algorithm HWWO performance is eval-
HEFT consistently generated the poorest schedules, trailing EPM and
uated across three scenarios and compared with several metaheuristic
ESRG. Initially, EPM underperformed compared to ESRG but surpassed
methods using various metrics. The evaluation considers different task
it as task count increased. In critical DAG path scenarios, DECM and
and processor configurations, as well as benchmark tests involving
REREC outperformed HEFT, EPM, and ESRG, regardless of input size.
unimodal functions. Additionally, experiments are conducted for tasks
Fig. 25 shows the average SLR performance of various algorithms scheduling in a multiprocessing environment, with input parameters
as a function of CCR. HEFT consistently exhibited the poorest SLR described in Table 18. After simulations, a comprehensive assessment
25
Karishma and H. Kumar Computer Standards & Interfaces 97 (2026) 104106
Table 16
Energy consumption assessment for GE applications with varying reliability criteria.
Reliability Performance Algorithm
goal metric HEFT DECM EPM REREC ESRG HWWO
0.91 Best 4.54E+4 3.45E+4 3.83E+4 3.53E+4 3.73E+4 2.55E+4
Mean 4.54E+4 3.45E+4 3.83E+4 3.53E+4 3.73E+4 2.55E+4
Worst 4.58E+4 3.45E+4 3.83E+4 3.53E+4 3.79E+4 2.55E+4
St. Dev 4.23E+2 4.13E4 5.24E4 1.13E4 6.34E2 5.24E8
0.92 Best 4.74E+4 3.77E+4 4.18E+4 3.96E+4 4.16E+4 2.88E+4
Mean 4.81E+4 3.78E+4 4.19E+4 3.98E+4 4.19E+4 2.88E+4
Worst 4.92E+4 3.78E+4 4.19E+4 3.98E+4 4.19E+4 2.88E+4
St. Dev 7.40E+2 4.27E1 7.04E+1 9.42E+1 2.04E+2 7.02E7
0.93 Best 5.74E+4 3.81E+4 4.28E+4 4.18E+4 4.28E+4 2.91E+4
Mean 5.74E+4 3.83E+4 4.33E+4 4.20E+4 4.33E+4 2.94E+4
Worst 5.74E+4 3.86E+4 4.47E+4 4.26E+4 4.47E+4 2.95E+4
St. Dev 3.28E4 4.40E+3 8.02E+2 3.30E+3 8.02E+2 1.69E+2
0.94 Best 6.64E+4 3.97E+4 4.93E+4 4.51E+4 4.97E+4 3.97E+4
Mean 6.69E+4 3.97E+4 4.93E+4 4.65E+4 4.98E+4 3.97E+4
Worst 6.74E+4 3.99E+4 4.93E+4 4.77E+4 4.98E+4 3.99E+4
St. Dev 4.08E+2 9.42E+1 7.12E+2 3.12E+2 4.13E+2 9.42E+1
0.95 Best 8.45E+4 6.52E+4 6.84E+4 6.63E+4 6.84E+4 4.44E+4
Mean 8.48E+4 6.52E+4 6.84E+4 6.67E+4 6.84E+4 4.46E+4
Worst 8.51E+4 6.59E+4 6.85E+4 6.67E+4 6.85E+4 4.53E+4
St. Dev 5.02E+3 3.72E4 4.07E+3 4.63E+3 4.07E+3 5.17E+2
0.96 Best 6.76E+4 6.90E+4 4.86E+4
Mean 6.78E+4 6.90E+4 4.86E+4
Worst 6.78E+4 6.90E+4 4.86E+4
St. Dev 3.72E2 4.63E5 4.06E13
0.97 Best 7.15E+4 7.25E+4 6.55E+4
Mean 7.18E+4 7.25E+4 6.55E+4
Worst 7.18E+4 7.25E+4 6.55E+4
St. Dev 4.03E+2 5.33E11 4.22E11
0.98 Best 9.37E+4 9.41E+4 7.31E+4
Mean 9.37E+4 9.41E+4 7.31E+4
Worst 9.37E+4 9.48E+4 7.37E+4
St. Dev 4.37E9 1.17E+2 4.52E4
0.99 Best
Mean
Worst
St. Dev
Fig. 23. Graphical representation of Table 16.
is carried out, calculating metrics such as average execution time, the algorithms effectiveness in terms of energy consumption, system
standard deviation, and mean across iterations. The results highlight reliability, resource utilization, and sensitivity analysis.
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Karishma and H. Kumar Computer Standards & Interfaces 97 (2026) 104106
Table 17
Average SLR for all algorithms with respect to various tasks (in case of GE).
|𝑋| Average SLR
HEFT DECM EPM REREC ESRG HWWO
90 6.3E+1 3.4E+1 4.4E+1 3.9E+1 4.0E+1 3.4E+1
230 7.2E+1 4.7E+1 5.8E+1 4.9E+1 5.4E+1 3.8E+1
495 8.9E+1 5.8E+1 6.6E+1 6.1E+1 6.2E+1 4.9E+1
1127 1.2E+2 7.8E+1 9.3E+1 8.5E+1 9.8E+1 7.2E+1
2555 1.3E+2 8.7E+1 9.5E+1 8.9E+1 9.8E+1 7.9E+1
Fig. 24. Graphical representation of Table 17.
Fig. 25. Graphical representation of SLR values with respect to CCR (in case of GE).
6.3.1. Scenario 1 of processors constant. The detailed findings and analysis are presented
subsequently.
The study aims to thoroughly evaluate the effectiveness of the pro-
posed HWWO-based approach by testing it with different numbers of Tasks range: 1001000
tasks. Seven well-known metaheuristic algorithms PSO, ACO, KH, DA, Processor count: 100
AHA, GWO, and WOA are employed alongside the HWWO algorithm.
These algorithms are utilized to assess the performance of the HWWO For an impartial and consistent evaluation, the parameter settings
technique when varying the number of tasks while keeping the number of the seven algorithms remained unchanged from their default values
27
Karishma and H. Kumar Computer Standards & Interfaces 97 (2026) 104106
Fig. 26. Graphical representation of Table 19.
applications that are randomly generated via a DAG genera-
Table 18 tor [100], where the deadline and reliability requirements for
Parameter setting for stage II. completing each application are calculated as 𝐷𝐿(𝐺) = 𝐿𝐵(𝐺)
Algorithm Parameter 1.4 and 𝑅𝑒(𝑔𝑜𝑎𝑙) (𝐺) = 0.90 respectively.
PSO [57] Inertia weight = 0.4-0.9 A Table 19 is presented that compares the energy consump-
Cognitive component = 1.50 tion results from the proposed algorithm against seven other
Social component= 2 metaheuristic algorithms. This allows a thorough analysis and
ACO [55] Evaporation rate = 0.2
Weight of pheromone on decision = 0.5
side-by-side comparison of the energy efficiencies across these
Weight of heuristic information on decision = 0.5 different solution techniques when dealing with the randomized
Q = 2 parallel application workloads with the specified deadlines.
KH [59] Foraging motion = 0.2 The data presented in Table 19 indicates that when evaluating
Induced motion = 0.006
performance metrics, the ACO algorithm consistently exhibits
Inertia weight = 0.5
DA [67] Separation weight = 0.12 higher energy consumption compared to the seven other algo-
Alignment weight = 0.12 rithms under consideration. In the initial stages, the AHA and DA
Cohesion weight = 0.75 algorithms deliver superior and comparable results to KH and
Food factor = 1 PSO, respectively. However, as the problem size scales up, the
Enemy factor =1
AHA [67] Inertia weight = 0.5
KH and PSO algorithms outperform AHA and DA, demonstrat-
Local search probability = 0.5 ing more efficient outcomes. Among the remaining algorithms,
GWO [29] 𝜇 = [0, 2] the GWO technique demonstrates its strength by outperforming
𝑙1 , 𝑙2 = [0,1] the WOA method while attaining comparable energy efficiency.
𝜁 = [1, 1] Strikingly, the newly proposed HWWO algorithm surpasses all
WOA [28] 𝜈 = [1, 1] the other contenders, exhibiting substantially lower energy con-
𝜇 = [0, 2] sumption levels. The HWWO algorithm establishes itself as the
𝑙1 , 𝑙2 = [0,1]
leading performer in terms of optimizing energy consumption
Proposed HWWO 𝑤̂ 𝑖,𝑙 (𝑚𝑠) = [10, 100]
𝑐̂𝑖,𝑘 (𝑚𝑠) = [10, 100] across the diverse set of test scenarios explored in this evalu-
𝑃𝑙,𝑠 = [0.1, 0.5] ation. The graphical representation in Fig. 26 depicts energy
𝑃𝑙,𝑖𝑛𝑑 = [0.03, 0.07] consumption levels across different sets of tasks. A clear pattern
𝐶𝑙,𝑒𝑓 = [0.8, 1.2] emerges: higher energy usage as more tasks is added. However,
𝑚𝑙 = [2.5, 3.0]
𝑓𝑙,𝑚𝑎𝑥 = 1 GHz
the proposed algorithms energy consumption values are notice-
𝜆𝑙,𝑚𝑎𝑥 = [0.0003, 0.0009] ably lower than existing methods, indicating superior efficiency.
For 100 processors, the HWWO algorithm minimizes energy con-
sumption by 18%24% less than GWO and WOA respectively.
This substantial reduction highlights the proposed approachs
as presented in Table 18. The findings accentuated the algorithms energy-saving advantages, especially with increasing tasks.
proficiency in several key areas, including energy efficiency, system ii System reliability
reliability, resource utilization, and sensitivity analysis across a range This part evaluates the proposed algorithms effectiveness by ex-
of input variations. amining reliability across varying task combinations. It analyzes
reliability metrics for different task counts, targeting a reliability
i Energy consumption goal of 𝑅𝑒(𝑚𝑖𝑛) (𝐺) ≤ 𝑅𝑒(𝑔𝑜𝑎𝑙) (𝐺) ≤ 𝑅𝑒(𝑚𝑎𝑥) (𝐺) or 0.88371 ≤
The goal of this evaluation is to assess the proposed algorithms 𝑅𝑒(𝑔𝑜𝑎𝑙) (𝐺) ≤ 0.98577 at 0.90. The evaluation utilizes randomly
performance by analyzing its energy consumption for different generated parallel applications with deadlines calculated as
combinations of tasks. The assessment utilizes a set of parallel
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Karishma and H. Kumar Computer Standards & Interfaces 97 (2026) 104106
Fig. 27. Reliability outcomes for metaheuristic algorithms with varying task numbers.
𝐷𝐿(𝐺) = 𝐿𝐵(𝐺) 1.4. Fig. 27 presents a comparative analysis the experimental findings validates that the proposed HWWO
of reliability results obtained from the proposed algorithm and approach facilitates more efficient resource utilization than the
seven other metaheuristic algorithms. This comparison enables a existing metaheuristic frameworks.
thorough assessment of reliability performance across these solu- iv Sensitivity analysis
tion techniques when handling randomized parallel application In this subsection, the performance of the proposed method is
workloads with specified deadlines. evaluated through sensitivity analysis. Sensitivity analysis is a
Fig. 27 highlights the performance metrics, indicating that the technique employed to ascertain the extent to which the output
ACO algorithm consistently exhibits lower system reliability of a model is influenced by variations in the input parameters.
compared to the seven other algorithms evaluated. Initially, It helps to identify the inputs that have the most significant
AHA and DA algorithms demonstrate superior and comparable influence on the output and assess the models robustness to
reliability results to KH and PSO respectively, but as the problem variations in these inputs.
size increases, the latter two outperform the former, exhibiting The assessment encompasses a variety of randomly generated
more efficient outcomes. Among the remaining algorithms, the parallel applications, where the application deadline is deter-
GWO technique outperforms the WOA method, while the newly mined by the formula 𝐷𝐿(𝐺) = 𝐿𝐵(𝐺) 1.4. In this evaluation,
proposed HWWO algorithm surpasses all other contenders, ex- the sensitivity of the proposed HWWO model is investigated
hibiting substantially higher reliability levels in most cases and concerning the completion time of tasks scheduling. The overall
maximizing system reliability by 8%9% more than GWO and completion time for HWWO and other existing metaheuristic
WOA for 100 processors. approaches is presented in Table 20 with varying task quantities,
iii Resource utilization for which a sensitivity analysis is conducted. The optimiza-
This meticulously designed study aims to evaluate the effec- tion problem is addressed using a One-at-a-Time (OAT) based
tiveness of the proposed algorithm by thoroughly examining method, where the proposed techniques performance is assessed
resource utilization across various task combinations. The exam- through sensitivity analysis.
ination of resource utilization [78,79] mainly focuses on com- From Table 20, it can be concluded that the proposed HWWO
putation time and compares it with other existing models. The technique gave superior outcomes compared to other techniques.
assessment encompasses a variety of randomly generated par- It decreased computation time by 46.07%, 47.59%, 43.81%,
allel applications, where the application deadline is determined 46.11%, 41.84%, 28.85%, and 30.27% in comparison to PSO,
by the formula 𝐷𝐿(𝐺) = 𝐿𝐵(𝐺) 1.4. To offer an in-depth and ACO, KH, DA, AHA, GWO, and WOA respectively. To further an-
thorough comparative analysis of resource utilization, Fig. 28 (in alyze the performance, the average sensitivity of each algorithm
%) has been carefully crafted. This figure showcases the optimal is calculated using the OAT technique, as detailed in Table 21.
results achieved by eight distinct metaheuristic algorithms. The table analysis shows the proposed HWWO model has the
Optimal resource utilization is a critical factor in achieving lowest average sensitivity ratio (0.19), indicating least sensitivity
profitability for heterogeneous computing systems. Higher re- to task number changes among the algorithms. This lower sen-
source utilization directly corresponds to increased profits for sitivity suggests HWWO is more robust and reliable for varying
service providers. The figure presents a comparative analysis workloads, making it preferable in environments with fluctuat-
of resource utilization between the proposed HWWO approach ing task quantities.
and established metaheuristic frameworks. The results indicate
that the HWWO algorithm demonstrates superior performance,
substantially enhancing resource utilization by 42%, 62%, 22%, 6.3.2. Scenario 2
42.48%, 21.86%, 11.83%, and 14% in comparison to PSO, ACO, This part focuses on an in-depth evaluation of the proposed HWWO-
KH, DA, AHA, GWO, and WOA respectively, across a range based approach by experimenting with different processor counts. The
of computational tasks. The empirical evidence derived from HWWO algorithm is tested alongside seven well-established meta-
heuristic algorithms: PSO, ACO, KH, DA, AHA, GWO, and WOA. These
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Karishma and H. Kumar Computer Standards & Interfaces 97 (2026) 104106
Table 19
Analysis of energy consumptions for varying tasks.
|𝑋| Performance Algorithm
metric PSO ACO KH DA AHA GWO WOA HWWO
100 Best 6.08E+3 6.32E+3 5.25E+3 5.82E+3 5.25E+3 3.57E+3 3.67E+3 3.52E+3
Mean 6.13E+3 6.37E+3 5.25E+3 5.84E+3 5.25E+3 3.57E+3 3.67E+3 3.52E+3
Worst 6.13E+3 6.37E+3 5.29E+3 5.84E+3 5.29E+3 3.57E+3 3.68E+3 3.52E+3
St. Dev 5.30E+1 7.23E+2 5.55E3 4.15E+1 5.55E3 1.13E13 4.61E4 1.13E13
200 Best 6.51E+3 6.74E+3 5.83E+3 6.31E+3 5.69E+3 3.92E+3 3.88E+3 3.88E+3
Mean 6.51E+3 6.79E+3 5.85E+3 6.31E+3 5.69E+3 3.93E+3 3.89E+3 3.89E+3
Worst 6.51E+3 6.79E+3 5.87E+3 6.35E+3 5.69E+3 3.95E+3 3.89E+3 3.89E+3
St. Dev 2.07E4 7.03E+1 3.33E+1 7.09E+1 3.08E7 5.12E+1 1.02E+1 1.02E+1
300 Best 6.97E+3 7.58E+3 6.42E+3 6.93E+3 6.31E+3 4.87E+3 4.64E+3 4.58E+3
Mean 6.99E+3 7.58E+3 6.49E+3 6.95E+3 6.33E+3 4.87E+3 4.66E+3 4.59E+3
Worst 6.99E+3 7.58E+3 6.49E+3 6.95E+3 6.38E+3 5.95E+3 4.69E+3 4.61E+3
St. Dev 7.35E+1 2.43E6 3.11E+2 7.61E+1 1.01E+1 4.02E1 3.12E+0 7.17E+1
400 Best 7.48E+3 7.98E+3 6.89E+3 7.23E+3 6.77E+3 6.05E+3 6.05E+3 6.05E+3
Mean 7.48E+3 7.99E+3 6.91E+3 7.28E+3 6.77E+3 6.05E+3 6.05E+3 6.05E+3
Worst 7.48E+3 7.99E+3 6.96E+3 7.28E+3 6.77E+3 6.05E+3 6.05E+3 6.05E+3
St. Dev 7.15E4 1.85E1 1.13E+2 4.25E4 1.33E4 3.02E8 3.02E8 3.02E8
500 Best 8.36E+3 9.39E+3 7.49E+3 8.16E+3 7.89E+3 6.76E+3 6.66E+3 6.57E+3
Mean 8.53E+3 9.46E+3 7.49E+3 8.23E+3 7.89E+3 6.81E+3 6.68E+3 6.65E+3
Worst 8.67E+3 9.51E+3 7.49E+3 8.27E+3 7.92E+3 6.81E+3 6.68E+3 6.65E+3
St. Dev 1.81E+1 1.33E+1 2.73E6 1.44E+0 4.53E+1 4.11E+3 5.00E+1 9.01E+3
600 Best 1.31E+4 1.63E+4 9.78E+3 1.53E+4 9.97E+3 8.77E+3 9.04E+3 8.52E+3
Mean 1.33E+4 1.67E+4 9.78E+3 1.55E+4 9.99E+3 8.79E+3 9.14E+3 8.52E+3
Worst 1.37E+4 1.67E+4 9.81E+3 1.59E+4 9.99E+3 8.93E+3 9.14E+3 8.52E+3
St. Dev 6.01E1 4.35E2 4.47E+0 2.33E4 3.43E2 9.11E1 7.12E+1 6.16E12
700 Best 1.83E+4 2.44E+4 1.41E+4 2.34E+4 1.83E+4 9.89E+3 1.03E+4 9.46E+3
Mean 1.83E+4 2.54E+4 1.49E+4 2.39E+4 1.83E+4 9.89E+3 1.11E+4 9.47E+3
Worst 1.83E+4 2.57E+4 1.58E+4 2.43E+4 1.83E+4 9.93E+3 1.22E+4 9.49E+3
St. Dev 3.01E8 6.63E+4 2.65E+2 2.73E+4 3.01E8 6.66E2 3.01E+2 3.22E6
800 Best 3.15E+4 3.51E+4 2.41E+4 3.35E+4 2.76E+4 1.52E+4 1.94E+4 1.06E+4
Mean 3.35E+4 3.51E+4 2.53E+4 3.35E+4 2.78E+4 1.64E+4 1.94E+4 1.06E+4
Worst 3.35E+4 3.51E+4 2.58E+4 3.37E+4 2.78E+4 1.64E+4 1.94E+4 1.06E+4
St. Dev 2.32E+4 2.32E7 4.08E+2 2.32E+1 8.22E+1 3.07E+4 8.17E8 3.07E8
900 Best 4.15E+4 4.22E+4 3.95E+4 4.19E+4 4.05E+4 3.51E+4 3.91E+4 2.55E+4
Mean 4.15E+4 4.22E+4 3.95E+4 4.22E+4 4.11E+4 3.55E+4 3.95E+4 2.55E+4
Worst 4.15E+4 4.27E+4 3.95E+4 4.29E+4 4.11E+4 3.55E+4 3.95E+4 2.55E+4
St. Dev 1.81E6 6.21E+0 5.15E12 1.81E+2 1.81E+1 8.25E+0 5.15E2 5.15E12
1000 Best 4.71E+4 5.28E+4 4.13E+4 5.08E+4 4.60E+4 3.81E+4 4.13E+4 3.25E+4
Mean 4.73E+4 5.32E+4 4.23E+4 5.13E+4 4.60E+4 3.85E+4 4.23E+4 3.41E+4
Worst 4.73E+4 5.32E+4 4.23E+4 5.13E+4 4.60E+4 3.85E+4 4.23E+4 3.47E+4
St. Dev 2.01E+1 6.08E+1 1.51E+3 8.08E+4 3.01E7 4.44E2 1.51E+3 6.61E+4
Table 20
Comparative analysis of task completion times across various metaheuristic techniques under varying tasks.
|𝑋| Algorithm
PSO ACO KH DA AHA GWO WOA HWWO
100 1.58E+2 1.58E+2 1.56E+2 1.56E+2 1.35E+2 9.57E+1 1.03E+2 7.62E+1
200 2.01E+2 2.01E+2 1.88E+2 1.98E+2 1.78E+2 1.68E+2 1.22E+2 8.98E+1
300 2.67E+2 2.58E+2 2.42E+2 2.51E+2 2.36E+2 2.18E+2 1.88E+2 1.07E+2
400 4.49E+2 4.68E+2 4.17E+2 4.38E+2 4.17E+2 2.75E+2 2.54E+2 1.59E+2
500 4.96E+2 4.96E+2 4.85E+2 5.09E+2 4.98E+2 3.12E+2 3.37E+2 2.32E+2
600 5.31E+2 5.53E+2 5.08E+2 5.63E+2 5.37E+2 3.78E+2 3.95E+2 2.98E+2
700 5.83E+2 5.96E+2 5.51E+2 5.93E+2 5.83E+2 4.39E+2 4.39E+2 3.55E+2
800 6.15E+2 6.58E+2 6.01E+2 6.55E+2 6.26E+2 5.07E+2 5.07E+2 3.83E+2
900 6.61E+2 7.12E+2 6.66E+2 7.09E+2 6.66E+2 5.61E+2 5.71E+2 4.02E+2
1000 7.11E+2 7.55E+2 6.76E+2 7.38E+2 6.88E+2 6.04E+2 6.04E+2 4.59E+2
Table 21
The average sensitivity for each algorithm of Table 20.
Algorithm PSO ACO KH DA AHA GWO WOA HWWO
Avg sensitivity 0.37 0.42 0.39 0.38 0.34 0.27 0.29 0.19
algorithms are employed to examine the performance of the HWWO The findings accentuated the algorithms proficiency in several key
method under varying numbers of processors, while maintaining a con- areas, including energy efficiency, system reliability, resource utiliza-
stant number of tasks. The detailed findings and analysis are presented tion, and sensitivity analysis across a range of input variations.
subsequently.
i Energy consumption
Processors range: 1001000 The goal of this evaluation is to assess the proposed algorithms
Task count: 1000 performance by analyzing its energy consumption for different
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Karishma and H. Kumar Computer Standards & Interfaces 97 (2026) 104106
Fig. 28. Comparative analysis graph of resource utilization for metaheuristic techniques with varying tasks.
Fig. 29. Energy consumption for metaheuristic algorithms with respect to varying processors.
combinations of processors. The assessment utilizes a set of mechanism, enabling the HWWO algorithm to outperform oth-
parallel applications that are randomly generated via a DAG ers and find better solutions. When tested with 1000 tasks,
generator [100], where the deadline and reliability requirements the HWWO algorithm reduced energy consumption by 13.46-
for completing each application are calculated as 𝐷𝐿(𝐺) = 23.81% compared to GWO and WOA, respectively. This sub-
𝐿𝐵(𝐺) 1.4 and 𝑅𝑒(𝑔𝑜𝑎𝑙) (𝐺) = 0.90 respectively. stantial reduction underscores the energy-saving advantages of
The energy consumption results displayed in Fig. 29 compare the proposed approach, especially as the number of processors
the proposed algorithm against other metaheuristic algorithms. increases.
The figure reveals that the ACO algorithm consistently consumes ii System reliability
more energy than the other algorithms evaluated. Among these This part evaluates the proposed algorithms effectiveness by
algorithms, the GWO technique outperforms the WOA method examining reliability across varying processors combinations. It
while achieving similar energy efficiency as the AHA algorithm. analyzes reliability metrics for different task counts, targeting
Notably, the proposed algorithm exhibits significantly lower a reliability goal of 𝑅𝑒(𝑚𝑖𝑛) (𝐺) ≤ 𝑅𝑒(𝑔𝑜𝑎𝑙) (𝐺) ≤ 𝑅𝑒(𝑚𝑎𝑥) (𝐺) or
energy consumption than existing methods, indicating superior 0.88371 ≤ 𝑅𝑒(𝑔𝑜𝑎𝑙) (𝐺) ≤ 0.98577 at 0.90. The evaluation uti-
efficiency. This is due to the proposed algorithm defining a cir- lizes randomly generated parallel applications with deadlines
cular neighborhood around solutions based on its encirclement calculated as 𝐷𝐿(𝐺) = 𝐿𝐵(𝐺) 1.4.
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Karishma and H. Kumar Computer Standards & Interfaces 97 (2026) 104106
Fig. 30. Reliability outcomes for metaheuristic algorithms with varying processor numbers.
Fig. 30 highlights the performance metrics, indicating that the to 47.94% compared to various metaheuristic techniques. Ad-
ACO algorithm consistently exhibits lower system reliability ditionally, Table 23 provides the average sensitivity of each
compared to the seven other algorithms evaluated. Among the algorithm, determined through the OAT technique, for further
algorithms, the GWO technique outperforms the WOA method, performance analysis.
while the newly proposed HWWO algorithm surpasses all other The table analysis unveils that the proposed HWWO model
contenders, exhibiting substantially higher reliability levels in demonstrates the minimal average sensitivity ratio (0.22), indi-
most cases and maximizing system reliability by 5%8% more cating its superior resistance to fluctuations in processor avail-
than GWO and WOA for 1000 tasks. ability compared to other algorithms. This lower sensitivity
iii Resource utilization makes HWWO more robust and reliable for different work-
This part intends to assess the efficacy of the proposed algo- loads, making it ideal for environments with varying processor
rithmic approach by conducting a comprehensive analysis of re- numbers.
source utilization across different processor configurations. The
assessment encompasses a variety of randomly generated par-
allel applications, where the application deadline is determined 6.3.3. Scenario 3
by the formula 𝐷𝐿(𝐺) = 𝐿𝐵(𝐺) 1.4. To offer an in-depth and To validate the proposed HWWO algorithms efficacy against es-
thorough comparative analysis of resource utilization, Fig. 31 (in tablished metaheuristic optimization techniques, this section employs
%) has been carefully crafted. This figure showcases the optimal a set of unimodal test functions. These benchmark functions, sourced
results achieved by eight distinct metaheuristic algorithms. from [28] and tabulated in Table 24, assess the algorithms exploita-
The results from figure indicate that the HWWO algorithm tion capabilities and overall optimization performance. Ensuring a fair
demonstrates superior performance, substantially enhancing re- comparison, all tests utilize a population size of 30, with a maximum
source utilization by 26.92%, 29.79%, 19.34%, 16.48%, 16.86%, of 15,000 function evaluations across 500 iterations. Each algorithm
9.83%, and 25.15% in comparison to PSO, ACO, KH, DA, AHA, is executed 30 times independently on these functions. The evaluation
GWO, and WOA respectively, across a range of computational metrics, including mean, standard deviation, best and worst fitness
processors. The empirical evidence derived from the experi- values from the independent runs, are then computed and presented
mental findings validates that the proposed HWWO approach in Table 25.
facilitates more efficient resource utilization than the existing An analysis of Table 25, which presents the results for unimodal
metaheuristic frameworks. functions, clearly demonstrates the superior exploitation capability of
iv Sensitivity analysis the proposed HWWO algorithm. This is evident from the fact that the
In this subsection, the effectiveness of the proposed method HWWO algorithm achieves the best mean fitness values in the majority
is assessed via sensitivity analysis in relation to different pro- of cases, as indicated by the bold entries. In contrast, the existing algo-
cessor counts. The assessment encompasses a variety of ran- rithms being evaluated display comparatively inferior performance.
domly generated parallel applications, where the application In evaluating the algorithms performance based on the highest
deadline is determined by the formula 𝐷𝐿(𝐺) = 𝐿𝐵(𝐺) 1.4. In fitness scores across 30 runs, it is observed that the HWWO algorithm
this evaluation, the sensitivity of the HWWO model concerning outperformed others, securing the highest number of best fitness scores
tasks scheduling completion times is explored. Table 22 displays (5/7). In comparison, WOA and GWO attained fewer best fitness scores
the overall completion times for HWWO and other existing (1/7 each), while all other algorithms do not achieve the best fitness
metaheuristic approaches across varying processors, for which in any of the runs. These results suggest that the HWWO algorithm
a sensitivity analysis is performed. demonstrates greater consistency and reliability in attaining optimal
Table 22 shows that the HWWO technique yielded better re- fitness values compared to others.
sults than other methods, reducing computation time by 30.68% The statistical analysis using the Wilcoxon signed-rank test is pre-
sented in Table 26, which evaluates the performance of the HWWO
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Karishma and H. Kumar Computer Standards & Interfaces 97 (2026) 104106
Table 22
Comparative analysis of task completion times across various metaheuristic techniques under varying processors.
|𝑌 | Algorithm
PSO ACO KH DA AHA GWO WOA HWWO
100 1.28E+2 1.28E+2 1.26E+2 9.56E+1 8.62E+1 8.02E+1 1.07E+2 6.82E+1
200 2.12E+2 2.21E+2 1.88E+2 1.88E+2 1.73E+2 1.64E+2 1.85E+2 8.88E+1
300 2.67E+2 2.71E+2 2.71E+2 2.51E+2 2.38E+2 2.38E+2 2.65E+2 1.17E+2
400 4.89E+2 4.98E+2 4.72E+2 4.48E+2 4.37E+2 2.84E+2 4.59E+2 1.54E+2
500 4.98E+2 5.21E+2 4.85E+2 5.19E+2 4.78E+2 3.62E+2 5.19E+2 2.22E+2
600 5.71E+2 5.73E+2 5.64E+2 5.62E+2 5.17E+2 3.73E+2 5.64E+2 2.98E+2
700 6.13E+2 6.26E+2 5.95E+2 5.89E+2 5.73E+2 4.49E+2 5.93E+2 3.75E+2
800 6.65E+2 6.68E+2 6.61E+2 6.46E+2 6.46E+2 5.17E+2 6.55E+2 3.86E+2
900 7.41E+2 7.52E+2 7.36E+2 7.15E+2 6.76E+2 5.61E+2 7.27E+2 4.32E+2
1000 7.53E+2 7.75E+2 7.46E+2 7.43E+2 6.91E+2 6.12E+2 7.43E+2 4.54E+2
Table 23
The average sensitivity for each algorithm of Table 22.
Algorithm PSO ACO KH DA AHA GWO WOA HWWO
Avg sensitivity 0.41 0.45 0.42 0.39 0.33 0.29 0.37 0.22
Fig. 31. Comparative analysis graph of resource utilization for metaheuristic techniques with varying processors.
Table 24
Description of unimodal benchmark functions.
Function Dimensions Range 𝑓𝑚𝑖𝑛
∑𝑛
𝐹1 = 𝑖=1 𝑥2𝑖 30 [100, 100] 0
∑𝑛 ∏𝑛
𝐹2 = 𝑖=1 |𝑥𝑖 | + 𝑖=1 |𝑥𝑖 | 30 [10, 10] 0
∑𝑛 (∑𝑖 )2
𝐹3 = 𝑖=1 𝑥
𝑗=1 𝑗
30 [100, 100] 0
𝐹4 = 𝑚𝑎𝑥𝑖 {|𝑥𝑖 |, 1 ≤ 𝑖𝑛} 30 [100, 100] 0
𝑛1 [ ]
𝐹5 = 𝑖=1 100(𝑥𝑖+1 𝑥2𝑖 )2 + (𝑥𝑖 1)2 30 [30, 30] 0
∑𝑛
𝐹6 = 𝑖=1 ([𝑥𝑖 + 0.5])2 30 [100, 100] 0
∑𝑛
𝐹7 = 𝑖=1 𝑖𝑥4𝑖 + 𝑟𝑎𝑛𝑑𝑜𝑚[0, 1) 30 [1.28, 1.28] 0
algorithm based on unimodal benchmark functions. This table shows that the proposed algorithm achieves superior performance in solving
the rank of the HWWO algorithm in comparison to the second algo- unimodal benchmark problems, demonstrating faster convergence and
rithm, focusing on the best fitness values. 𝑇 + represents the superiority greater accuracy compared to existing methods.
of the proposed HWWO technique. P-values, calculated at a 5% signifi-
Finally, the convergence behavior of the proposed HWWO algo-
cance level, test the null hypothesis that the median difference between
rithm is depicted through convergence curves compared with other
the algorithms is zero. The final row of Table 26 consolidates the counts
algorithms in Fig. 32. The convergence rate, which evaluates an al-
of 𝑇 + and 𝑇 , along with the test statistic, offering a clear summary of
gorithms efficiency in reaching the optimal solution, is analyzed by
the results. The analysis reveals significant improvements in the HWWO
comparing HWWOs performance with existing metaheuristic tech-
algorithms performance, with 𝑇 + accounting for 93.87% and 𝑇 for
niques. In the graph, the 𝑥-axis represents the number of iterations,
6.12% of the evaluated benchmarks (𝑝 < 0.05). These results suggest
while the 𝑦-axis shows the average fitness values computed over 1000
33
Karishma and H. Kumar Computer Standards & Interfaces 97 (2026) 104106
Table 25
Outcomes of using unimodal functions.
F Measure Optimization algorithm
PSO ACO KH DA AHA GWO WOA HWWO
𝐹1 Best 1.709E13 1.471E10 1.660E19 1.835E13 3.003E49 3.010E79 5.763E60 3.755E94
Mean 8.644E11 1.121E09 6.660E17 4.992E12 9.206E48 2.013E67 1.847E57 2.401E87
Worst 2.483E10 6.170E09 5.873E16 3.849E11 2.162E47 8.057E67 9.399E57 8.552E87
St. Dev 1.889E01 7.223E04 1.861E01 3.046E03 1.418E47 3.413E72 2.149E03 4.027E72
𝐹2 Best 5.069E12 8.035E06 1.803E34 1.609E09 7.112E29 4.925E55 2.757E65 2.283E80
Mean 9.183E11 1.290E03 6.257E33 1.325E08 1.116E28 2.350E52 9.432E45 5.662E60
Worst 2.272E10 5.056E03 1.230E32 3.626E08 1.931E28 9.217E52 3.775E44 2.220E59
St. Dev 9.594E11 2.511E03 6.834E33 1.611E08 5.517E27 3.559E52 1.088E44 1.106E59
𝐹3 Best 5.077E07 5.783E02 2.497E06 3.273E26 3.156E05 3.10E128 6.837E03 6.389E28
Mean 3.377E01 1.123E+00 8.221E05 1.984E24 9.296E03 2.683E82 1.808E02 2.711E27
Worst 1.350E+00 3.310E+00 1.607E04 7.912E24 3.513E02 1.073E81 4.471E02 1.080E26
St. Dev 6.753E01 1.481E+00 8.191E05 3.952E24 1.723E02 5.367E82 1.784E02 5.398E27
𝐹4 Best 7.275E04 1.655E03 5.300E17 3.102E05 1.969E54 2.551E21 1.388E62 2.277E78
Mean 1.654E02 5.793E02 8.969E16 2.358E04 2.149E49 1.030E19 2.346E43 2.971E53
Worst 4.365E02 1.838E01 1.704E15 4.706E04 8.596E49 3.632E19 9.346E43 1.188E52
St. Dev 1.975E02 8.624E02 8.320E16 2.214E04 4.297E49 1.741E19 4.667E43 5.942E53
𝐹5 Best 7.65461E 7.68388E 9.70569E 3.126E01 6.15363E 4.291E02 1.18142E 3.113E04
Mean 7.99255E 8.42474E 5.91556E+02 2.924E+00 6.68606E 7.121E01 4.65548E 1.267E03
Worst 8.42156E 9.31820E 1.20253E+03 5.389E+00 7.23273E 1.596E+00 6.10117E 2.696E03
St. Dev 3.32511E01 7.36628E01 5.00585E+02 2.924E+00 6.07412E1 7.068E01 2.32924E 1.013E03
𝐹6 Best 3.543E01 7.685E05 3.620E06 9.22444E10 2.039E03 2.907E16 6.490E20 1.549E12
Mean 6.382E01 6.237E03 4.380E06 1.23821E09 4.113E03 7.377E14 3.630E16 7.981E11
Worst 8.362E01 1.772E02 4.993E06 1.62791E09 7.156E03 2.903E13 1.324E15 1.891E10
St. Dev 2.061E01 1.444E13 5.766E07 2.97023E10 2.229E03 8.229E03 6.436E16 9.242E11
𝐹7 Best 3.457E03 6.312E03 8.926E04 9.48224E04 2.857E04 3.366E05 1.03E+4 6.443E06
Mean 9.097E03 2.395E02 1.791E03 1.97178E03 6.290E04 2.899E04 1.11E+4 2.188E04
Worst 2.001E02 5.483E02 2.728E03 3.58221E03 8.085E04 8.911E04 1.22E+4 5.489E04
St. Dev 7.412E03 2.124E02 7.973E04 1.24604E03 2.388E04 4.095E04 3.01E+2 2.247E04
Table 26
Results of Wilcoxon signed-rank test of Table 25.
Problem HWWO vs PSO HWWO vs ACO HWWO vs KH HWWO vs DA HWWO vs AHA HWWO vs GWO HWWO vs WOA
Rank Rank Rank Rank Rank Rank Rank
𝐹1 1 1 2 2 2 1 3
𝐹2 2 2 1 4 3 2 1
𝐹3 3 6 4 1 4 3 5
𝐹4 4 4 3 5 1 4 2
𝐹5 7 7 7 7 7 7 6
𝐹6 6 3 5 3 6 5 4
𝐹7 5 5 6 6 5 6 7
p-value 0.0355 0.0013 0.0281 0.0176 0.0262 0.0474 0.0087
𝑇 + = Sum of positive number ranks 28 28 28 28 28 20 24
𝑇 = Sum of negative number ranks 0 0 0 0 0 8 4
𝑇 = min(𝑇 + , 𝑇 ) 0 0 0 0 0 8 4
tasks using 100 processors. For clarity, the graph illustrates the average reflecting its well-balanced integration of exploration and exploitation
fitness values from 10 independent runs, each evaluated over 500 for enhanced optimization performance.
iterations. As shown in Fig. 32, the HWWO algorithm demonstrates
rapid convergence toward optimal solutions, outperforming other algo-
7. Conclusions
rithms. This superior performance stems from HWWOs hybrid design,
which integrates the strengths of WOA and GWO. By combining these
To address the challenge of tasks scheduling in a heterogeneous
techniques, HWWO effectively overcomes the limitations of premature
distributed computing environment, this research proposes a hybrid
and slow convergence inherent in WOA. The figure underscores the lim-
meta-heuristic technique called HWWO, which amalgamates the WOA
itations of PSO and ACO algorithms, primarily their weak exploitation
and the GWO. The paper presents a reliability-based energy-efficient
capabilities. Despite iterating extensively through the solution space,
scheduling model designed to reduce energy consumption and enhance
these algorithms often fail to reach the optimal solution due to an
the reliability of applications running on heterogeneous computing
imbalance between exploration and exploitation phases. Similarly, DA
platforms, all while adhering to strict deadline requirements. The ap-
and KH exhibit strong exploratory abilities in the initial stages but
plications are elegantly modeled using DAGs. The article proposes a
frequently become trapped in local optima, preventing convergence
novel scheduling algorithm that combines the WOA and the GWO with
to the optimal solution. In contrast, WOA initially outperforms GWO
DVFS capabilities, along with an insert-reversed block operation. This
in generating promising solutions, but GWO surpasses WOA in later
hybrid approach aims to minimize both static and dynamic energy
iterations by refining the search process. HWWO, however, demon-
consumption. The article presents a refined technique to simultaneously
strates steady improvement in fitness value with increasing iterations,
tackle the challenges of tasks scheduling on appropriate processors
while considering multiple objectives. The proposed method seeks to
34
Karishma and H. Kumar Computer Standards & Interfaces 97 (2026) 104106
Fig. 32. Comparison of convergence curves of HWWO and literature algorithms.
optimize overall energy consumption, computational time, and system HWWO consistently demonstrated the minimal average sensi-
reliability concurrently, offering a comprehensive solution to address tivity ratio and rapid convergence towards optimal solutions,
these critical factors. Extensive experiments highlight the proposed outperforming existing metaheuristic algorithms.
models effectiveness in considerably reducing energy consumption and vii A Wilcoxon-signed rank test is utilized to statistically evaluate
processing time, increasing system reliability, and maintaining low the effectiveness of the results.
complexities. The key contributions based on experimental findings are: viii The run time and space complexities for the proposed method
are calculated, both equating to 𝑂(|𝑌 | |𝑋|) + 𝑂(|𝑌 |). Notably,
i The article introduces a hybrid scheduling mechanism, termed in terms of complexities, the proposed algorithm demonstrates
HWWO, that integrates SI techniques, specifically WOA and the superior performance compared to other existing algorithms in
GWO, to tackle real-world applications effectively. this domain.
ii The WOA algorithm exhibits rapid convergence and strikes a
balance between exploration and exploitation when solving op-
timization problems. However, its encircling search mechanism 7.1. Limitations and future work
can occasionally lead it to converge prematurely on local optima.
To mitigate this issue, a hybrid approach has been devised
by incorporating the GWO, synergizing the capabilities of both In this article, a hybrid model is developed to solve the reliability-
optimization techniques. based energy-efficient tasks scheduling problem with multiple objec-
iii Extensive evaluations are conducted on real-world FFT and tives. The model successfully reduces total energy consumption com-
GE applications to compare the proposed models performance pared to existing methods, although it fails to reduce static energy
against various state-of-the-art methods. consumption individually. As shown in Tables 12 and 16, the proposed
iv The proposed algorithm is rigorously evaluated on real-world HWWO approach exhibits superior energy consumption performance
single-objective constrained optimization problems from the for reliability thresholds up to 0.98. However, beyond this threshold,
CEC 2020 competition. Comprehensive comparisons are con- the method fails to meet reliability constraints due to the absence of
ducted against the competitions state-of-the-art algorithms, in- fault-tolerance mechanisms, indicating that 𝑅𝑒(𝑔𝑜𝑎𝑙) (𝐺) cannot always
cluding SASS, EnMODE, sCMAgES, and COLSHADE. Addition- be satisfied. Addressing these limitations, future research will focus
ally, the algorithms performance is assessed on a set of uni- on integrating fault-tolerance mechanisms into the hybrid model more
modal benchmark test functions and compared to established efficiently. This integration could involve implementing error detection
metaheuristic approaches. and correction techniques and robust optimization strategies to ensure
v The experiments reveal the proposed algorithms superiority continuous and accurate tasks scheduling, even in the presence of
over existing state-of-the-art and metaheuristic methods. It ex- faults.
cels in energy efficiency, reliability maximization, computation The method is effective within computing environments where
time and SLR minimization, CCR optimization, and resource uti- processors are fully connected. To address its limitations, enhancing the
lization enhancement across diverse scale conditions and dead- framework involves refining scheduling algorithms and assessing them
line constraints. across various workflows such as LIGO, SIPHT, and molecular dynamic
vi The effectiveness and scalability of the proposed HWWO method code. Furthermore, the proposed frameworks versatility allows for
are assessed through sensitivity analysis and implementation on potential extensions to diverse computing system environments such
varying tasks and processor counts. The outcomes revealed that as grid computing, cloud computing, and cluster computing.
35
Karishma and H. Kumar Computer Standards & Interfaces 97 (2026) 104106
CRediT authorship contribution statement [13] H. Xu, R. Li, C. Pan, K. Li, Minimizing energy consumption with reliability goal
on heterogeneous embedded systems, J. Parallel Distrib. Comput. 127 (2019)
4457, http://dx.doi.org/10.1016/j.jpdc.2019.01.006.
Karishma: Writing original draft, Validation, Software, Resources,
[14] L. Zhang, M. Ai, K. Liu, J. Chen, K. Li, Reliability enhancement strategies for
Methodology, Investigation, Data curation, Conceptualization. Haren- workflow scheduling under energy consumption constraints in clouds, IEEE
dra Kumar: Validation, Supervision, Methodology, Investigation, For- Trans. Sustain. Comput. 9 (2) (2024) 155169, http://dx.doi.org/10.1109/
mal analysis, Conceptualization. TSUSC.2023.3314759.
[15] L. Zhang, K. Li, K. Li, Y. Xu, Joint optimization of energy efficiency and system
reliability for precedence constrained tasks in heterogeneous systems, Int. J.
Funding Electr. Power Energy Syst. 78 (2016) 499512, http://dx.doi.org/10.1016/j.
ijepes.2015.11.102.
The authors declare that no funds, grants, or other support were [16] G. Xie, H. Peng, Z. Li, J. Song, Y. Xie, R. Li, K. Li, Reliability enhancement
toward functional safety goal assurance in energy-aware automotive cyber-
received during the preparation of this manuscript.
physical systems, IEEE Trans. Ind. Informatics 14 (12) (2018) 54475462,
http://dx.doi.org/10.1109/TII.2018.2854762.
Ethics approval and consent to participate [17] L. Ye, Y. Xia, S. Tao, C. Yan, R. Gao, Y. Zhan, Reliability-aware and energy-
efficient workflow scheduling in IaaS clouds, IEEE Trans. Autom. Sci. Eng. 20
(3) (2023) 21562169, http://dx.doi.org/10.1109/TASE.2022.3195958.
This article does not contain any studies with human participants
[18] X. Xiao, G. Xie, C. Xu, C. Fan, R. Li, K. Li, Maximizing reliability of energy con-
or animals performed by any authors. strained parallel applications on heterogeneous distributed systems, J. Comput.
Sci. 26 (2018) 344353, http://dx.doi.org/10.1016/j.jocs.2017.05.002.
Declaration of competing interest [19] G. Xie, Y. Chen, Y. Liu, Y. Wei, R. Li, K. Li, Resource consumption cost
minimization of reliable parallel applications on heterogeneous embedded
systems, IEEE Trans. Ind. Informatics 13 (4) (2016) 16291640, http://dx.doi.
The authors declare that they have no known competing finan- org/10.1109/TII.2016.2641473.
cial interests or personal relationships that could have appeared to [20] H. Djigal, J. Feng, J. Lu, J. Ge, IPPTS: An efficient algorithm for scientific
influence the work reported in this paper. workflow scheduling in heterogeneous computing systems, IEEE Trans. Parallel
Distrib. Syst. 32 (5) (2021) 10571071, http://dx.doi.org/10.1109/TPDS.2020.
3041829.
Data availability [21] Z. Deng, Z. Yan, H. Huang, H. Shen, Energy-aware task scheduling on
heterogeneous computing systems with time constraint, IEEE Access 8 (2020)
Data will be made available on request. 2393623950, http://dx.doi.org/10.1109/ACCESS.2020.2970166.
[22] Z. Quan, Z.-J. Wang, T. Ye, S. Guo, Task scheduling for energy consumption
constrained parallel applications on heterogeneous computing systems, IEEE
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