ArticlePublisher preview available

Multi-objective optimization of greening scheduling problems of part feeding for mixed model assembly lines based on the robotic mobile fulfillment system

Authors:
To read the full-text of this research, you can request a copy directly from the authors.

Abstract and Figures

Since greening scheduling problems are drawing increasing attention from researchers and modern manufacturing enterprises, and the energy consumption is a substantial problem regarding the greening and sustainability, the aim of this paper is to construct an energy-saving scheduling scheme to carry out the part feeding tasks of mobile robots in the automobile mixed model assembly lines. The objective of minimizing the total energy consumption of mobile robots is jointly incorporated with the operational criterions when implementing part feeding tasks. Due to the NP-hardness nature of the proposed greening problem, a multi-objective disturbance and repair strategy enhanced cohort intelligence (MDRCI) algorithm is established to deal with the multi-objective problem. Computational results indicate that the enhanced strategies are of great significance to the MDRCI algorithm and it outperforms the other benchmark algorithms on both global search capability and search depth. In addition, the energy-saving strategy and disturbance and repair strategy are validated by comparison experiments. Furthermore, managerial insights are illustrated to make trade-offs between the total line-side inventory level and the energy consumption, jointly making it helpful in the greening scheduling process of the practical production. The achievements acquired in this paper may be inspiring for further researches on the energy-related production scheduling problem.
This content is subject to copyright. Terms and conditions apply.
ORIGINAL ARTICLE
Multi-objective optimization of greening scheduling problems of part
feeding for mixed model assembly lines based on the robotic mobile
fulfillment system
Binghai Zhou
1
Zhexin Zhu
1
Received: 18 August 2020 / Accepted: 20 January 2021 / Published online: 2 March 2021
ÓThe Author(s), under exclusive licence to Springer-Verlag London Ltd. part of Springer Nature 2021
Abstract
Since greening scheduling problems are drawing increasing attention from researchers and modern manufacturing
enterprises, and the energy consumption is a substantial problem regarding the greening and sustainability, the aim of this
paper is to construct an energy-saving scheduling scheme to carry out the part feeding tasks of mobile robots in the
automobile mixed model assembly lines. The objective of minimizing the total energy consumption of mobile robots is
jointly incorporated with the operational criterions when implementing part feeding tasks. Due to the NP-hardness nature
of the proposed greening problem, a multi-objective disturbance and repair strategy enhanced cohort intelligence (MDRCI)
algorithm is established to deal with the multi-objective problem. Computational results indicate that the enhanced
strategies are of great significance to the MDRCI algorithm and it outperforms the other benchmark algorithms on both
global search capability and search depth. In addition, the energy-saving strategy and disturbance and repair strategy are
validated by comparison experiments. Furthermore, managerial insights are illustrated to make trade-offs between the total
line-side inventory level and the energy consumption, jointly making it helpful in the greening scheduling process of the
practical production. The achievements acquired in this paper may be inspiring for further researches on the energy-related
production scheduling problem.
Keywords Multi-objective optimization Greening scheduling Part feeding Mobile robot
1 Introduction
Due to the increasing global energy shortage, climate
deterioration and environmental issues, the greening
development of modern manufacturing enterprises has
become one of the toughest challenges faced with
humanity. Since production activities are responsible for
nearly 90% of greenhouse gas (GHG) emissions, reducing
the energy consumption and improving the energy effi-
ciency in the industrial sector inevitably led researchers
and manufacturers to pay serious attention to [1]. Under the
circumstance, practices on energy waste reduction through
energy-aware production scheduling methods are now
given great priority to among many enterprises’ cardinal
tasks [2], and the concept of ‘greening material handling
scheduling (GMHS)’ and ‘energy-efficient part feeding
problem (EPFP)’ has become attractive topics in both
practical applications and academic research. Therefore,
much advancement and increasing effort have been devo-
ted to exploit novel part feeding equipment and propulsion
technologies such as industrial robots, sensing devices and
new scheduling techniques [3].
However, though the utilization of industrial handling
robots can control GHG emissions, cut down production
costs and green the industry to a considerable degree [4,5],
it still consumes a large amount of electrical energy.
According to the International Federation of Robotics,
from 2013 to 2018, the global industrial robot market size
has exhibited a steady upward trend and has reached 168.2
billion dollars in 2018, twice as much as in 2013. These
&Binghai Zhou
bhzhou@tongji.edu.cn
Zhexin Zhu
zhuzhexin@163.com
1
School of Mechanical Engineering, Tongji University,
Shanghai 201804, People’s Republic of China
123
Neural Computing and Applications (2021) 33:9913–9937
https://doi.org/10.1007/s00521-021-05761-w(0123456789().,-volV)(0123456789().,-volV)
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
... The goal is to make them more transparent by discarding the need for metaphors. Some examples used in RMFS include Genetic Algorithms [34], Adaptive Large Neighborhood Search and Simulated Annealing [11], and Multi-Objective Disturbance and Repair Strategy Enhanced Cohort intelligence [35]. ...
... So, most authors have targeted less than five workstations. In contrast, the paper with the highest number of workstations is the one from Zhou et al. [35]. In said work, the authors considered up to 50 workstations, although this work represents an outlier. ...
... But within this great variety, few authors have pitted different techniques against each other. There were only seven papers in which authors compared different techniques [20], [21], [26], [35], [54], [61], [62]. In our opinion, this number should be higher and efforts should be allocated into comparing different types of techniques that have exhibited good results. ...
Article
Full-text available
The Robotic Mobile Fulfillment System (RMFS) is a method for handling products, in which a Line Follower Robot (LFR) transports products to a human workstation for packing. In this systematic review, we delve into the current state of RMFS research using data sourced from Scopus. After a comprehensive search, we found 264 manuscripts, which we filtered to 76 relevant articles. Our analysis covers several variables, from basic metadata to manuscript impact and specific conditions the authors consider. We discovered that there needs to be more focus on the pod allocation problem, despite its potential, with the majority of the emphasis on LFR displacement. We created a detailed diagram that outlines the essential elements and subproblems associated with RMFS. As the interest in RMFS continues growing, our study provides crucial insights and direction for future research efforts.
... human-centred objectives) as a potential research direction for large-scale robotic picking systems, there is relatively little literature in this field. For example, Zhou and Zhu (2021) consider greening scheduling problems for part feeding at mixed-model assembly lines based on the RMFS. They propose a multi-objective method called MDRCI to solve the problem. ...
... A practical multi-objective reliability optimisation model for integrating the scheduling of AGV and JSP is developed, and the problem is solved by a novel non-dominated sorted cuckoo search algorithm [32]. Zhou et al. [33] designed a cluster intelligence algorithm with multi-objective disturbance and repair strategies to minimise the TEC of a mobile robot combined with operational criteria. ...
Article
Full-text available
This study investigates the integrated multi-objective scheduling problems of job shops and material handling robots (MHR) with minimising the maximum completion time (makespan), earliness or tardiness, and total energy consumption. The collaborative scheduling of MHR and machines can enhance efficiency and reduce costs. First, a mathematical model is constructed to articulate the concerned problems. Second, three meta-heuristics, i.e., genetic algorithm (GA), differential evolution, and harmony search, are employed, and their variants with seven local search operators are devised to enhance solution quality. Then, reinforcement learning algorithms, i.e., Q-learning and state–action–reward–state–action (SARSA), are utilised to select suitable local search operators during iterations. Three reward setting strategies are designed for reinforcement learning algorithms. Finally, the proposed algorithms are examined by solving 82 benchmark instances. Based on the solutions and their analysis, we conclude that the proposed GA integrating SARSA with the first reward setting strategy is the most competitive one among 27 compared algorithms.
... In view of the NP-hard nature of the BOGSP-FMC, exact methods including dynamic programming, branch & bound and column generation are difficult to find acceptable solutions in a short time, especially when the problem size is large (Zhou and He 2020;Zhou and Zhu 2021a). To solve such complex multi-objective optimization problems in a reasonable time, many novel intelligent optimization algorithms have been developed and successfully applied to production scheduling problems in the literature, such as multi-objective grey wolf optimizer (Mirjalili et al. 2016), structure enhanced discrete non-dominated sorting genetic algorithm-II (NSGA-II) (Tan et al. 2022) and ant colony optimization (ACO) behavior-based multi-objective evolutionary algorithm based on decomposition (MOEA/ D) (Shao et al. 2022). ...
Article
Full-text available
Energy-awareness in the industrial sectors has become a global consensus in recent decades. Green scheduling is acknowledged as an effective weapon to reduce energy consumption in the industrial sectors. Therefore, this paper is devoted to the green scheduling of flexible manufacturing cells (FMC) with auto-guided vehicle transportation, where conflict-free routing of the vehicles is considered. To deal with this problem, a bi-objective optimization model is proposed to achieve the minimization of the maximum completion time and the total energy consumption in an FMC. The studied problem is an extension of flexible job shop problem which is NP-hard. Thus, an improved bi-objective salp swarm algorithm based on decomposition (IMOSSA/D) is proposed and applied to the problem. The approach is based on the decomposition of the bi-objective problem. Salp swarm intelligence along with three stochastic-distribution-based operators are incorporated into the approach, to enhance and balance its exploring and exploiting ability. Computational experiments are performed to compare the proposed approach with two state-of-the-art algorithms. This study allows the decision makers to better trade-off between energy savings and production efficiency in flexible manufacturing cellular environment.
Article
Full-text available
The total cost of assembly is a critical factor in robotic assembly line balancing, as it encompasses all the costs associated with the assembly line, including initial costs, setup, maintenance, and energy cost. This study introduces a different approach to the robotic assembly line balancing problem, with a dual focus on minimizing both cycle time and overall assembly costs. The effectiveness of the proposed approach is validated through three case study problems taken from the literature and results are compared to traditional assembly allocation methods. For case study 1, 89.4% (42 out of 47) of the solutions achieved a lower total cost, and 34% (16 out of 47) of the solutions utilized fewer workstations; and for case study 2, 96.4% (108 out of 112) of the solutions achieved a lower total cost, and 58.9% (66 out of 112) of the solutions utilized fewer workstations for the same cycle time. These results demonstrate a significant savings in cost and a notable improvement in workstation efficiency for a substantial portion of the solutions. This comprehensive approach allows an effective resource allocation, reduces inefficiencies, and enhances the overall cost-effectiveness and performance of the robotic assembly line. It also supports decision-makers in selecting more sustainable and economically viable assembly line solutions that optimize both productivity and energy efficiency.
Article
Purpose Owing to the finite nature of the boundary of the line (BOL), the conventional method, involving the strong matching of single-variety parts with storage locations at the periphery of the line, proves insufficient for mixed-model assembly lines (MMAL). Consequently, this paper aims to introduce a material distribution scheduling problem considering the shared storage area (MDSPSSA). To address the inherent trade-off requirement of achieving both just-in-time efficiency and energy savings, a mathematical model is developed with the bi-objectives of minimizing line-side inventory and energy consumption. Design/methodology/approach A nondominated and multipopulation multiobjective grasshopper optimization algorithm (NM-MOGOA) is proposed to address the medium-to-large-scale problem associated with MDSPSSA. This algorithm combines elements from the grasshopper optimization algorithm and the nondominated sorting genetic algorithm-II. The multipopulation and coevolutionary strategy, chaotic mapping and two further optimization operators are used to enhance the overall solution quality. Findings Finally, the algorithm performance is evaluated by comparing NM-MOGOA with multi-objective grey wolf optimizer, multiobjective equilibrium optimizer and multi-objective atomic orbital search. The experimental findings substantiate the efficacy of NM-MOGOA, demonstrating its promise as a robust solution when confronted with the challenges posed by the MDSPSSA in MMALs. Originality/value The material distribution system devised in this paper takes into account the establishment of shared material storage areas between adjacent workstations. It permits the undifferentiated storage of various part types in fixed BOL areas. Concurrently, the innovative NM-MOGOA algorithm serves as the core of the system, supporting the formulation of scheduling plans.
Article
Purpose Driven by sustainable production, mobile robots are introduced as a new clean-energy material handling tool for mixed-model assembly lines (MMALs), which reduces energy consumption and lineside inventory of workstations (LSI). Nevertheless, the previous part feeding scheduling method was designed for conventional material handling tools without considering the flexible spatial layout of the robotic mobile fulfillment system (RMFS). To fill this gap, this paper focuses on a greening mobile robot part feeding scheduling problem with Just-In-Time (JIT) considerations, where the layout and number of pods can be adjusted. Design/methodology/approach A novel hybrid-load pod (HL-pod) and mobile robot are proposed to carry out part feeding tasks between material supermarkets and assembly lines. A bi-objective mixed-integer programming model is formulated to minimize both total energy consumption and LSI, aligning with environmental and sustainable JIT goals. Due to the NP-hard nature of the proposed problem, a chaotic differential evolution algorithm for multi-objective optimization based on iterated local search (CDEMIL) algorithm is presented. The effectiveness of the proposed algorithm is verified by dealing with the HL-pod-based greening part feeding scheduling problem in different problem scales and compared to two benchmark algorithms. Managerial insights analyses are conducted to implement the HL-pod strategy. Findings The CDEMIL algorithm's ability to produce Pareto fronts for different problem scales confirms its effectiveness and feasibility. Computational results show that the proposed algorithm outperforms the other two compared algorithms regarding solution quality and convergence speed. Additionally, the results indicate that the HL-pod performs better than adopting a single type of pod. Originality/value This study proposes an innovative solution to the scheduling problem for efficient JIT part feeding using RMFS and HL-pods in automobile MMALs. It considers both the layout and number of pods, ensuring a sustainable and environmental-friendly approach to production.
Article
Full-text available
Facing the two major challenges of just-in-time (JIT) and energy-saving in part-feeding system for mixed-model assembly lines in automotive industry, this paper focuses on optimizing the part-feeding process by investigating the autonomous guided vehicles (AGV) routing and scheduling problem. A hybrid feeding policy, called dual-distribution, is proposed, which considers the utilization of different types of AGVs in various part-feeding policies. The problem is formulated as a mixed-integer programming model with the objectives of simultaneously minimizing the line-side inventory and AGV energy consumption in the part-feeding system. To solve this problem, a Q-learning-based multi-objective quantum-inspired Archimedes optimization algorithm (QMQAOA) is developed with a customized encoding and decoding approach to solve the problem. Besides, the quantum rotation gate initialization mechanism, the Q-learning-based neighborhood search strategy, and the neighboring distance calculation are integrated into the algorithm to improve both solution quality and convergence rate. Finally, numerical experiments are conducted to evaluate the performance of QMQAOA by comparing it with the Gurobi solver and other benchmark algorithms. The results demonstrate the superiority of QMQAOA, with performance superiority rates of 90/90, 77/90, and 90/90 achieved for degree of Pareto optimality (DPO), evenness of solutions (ES), and inverted generational distance (IGD) indicators, respectively. From managerial insights, the application of different types of AGVs in the part-feeding system is shown to enhance efficiency when compared to using a single type of AGV in several instances. These findings provide valuable insights for optimizing the automotive part-feeding system.
Article
Full-text available
In recent years, several nature-inspired optimization methods have been proposed and applied on various classes of problems. The applicability of the recently developed socio-inspired optimization method referred to as multi-cohort intelligence (Multi-CI) is validated by solving real-world problems from manufacturing processes domain, viz. non-traditional manufacturing processes. The problems are minimization of surface roughness for abrasive water jet machining (AWJM), electro-discharge machining (EDM), micro-turning and micro-milling processes. Furthermore, the taper angle for the AWJM, relative electrode wear rate for EDM, burr height and burr thickness for micro-drilling, flank wear for micro-turning process, machining time for micro-milling processes were minimized. It is important to mention that for the micro-drilling and micro-milling process different tool specifications were used. In addition, for EDM the material removal rate was maximized. The performance of the algorithm has been validated by comparing the results with other variations of CI algorithm and several contemporary algorithms such as firefly algorithm, genetic algorithm, simulated annealing and particle swarm optimization. In AWJM, Multi-CI achieved 5–8% and 8–23% minimization for surface roughness and taper angle, respectively. For EDM, 47–80% maximization of material removal rate; 2–13% and 92–98% minimization of surface roughness and relative electrode wear rate, respectively, have been attained. Furthermore, for micro-turning 2% minimization of flank wear and for micro-milling, 2–6% minimization of machining time were attained. For micro-drilling, 24% and 16–34% minimization of burr height and burr thickness were attained. In addition, the performance is compared with the regression and response surface methodology approaches and experimental solutions. The analysis regarding the convergence of all the algorithms is discussed in detail. The contributions in this paper have opened up several avenues for further applicability of the Multi-CI algorithm for solving real-world problems.
Article
Full-text available
Many engineering optimization problems are typically multi-objective in their natures and multidisciplinary with a large number of decision variables. Furthermore, Pareto dominance loses its effectiveness in such situations. Thus, developing a robust optimization algorithm undoubtedly becomes a true challenge. This paper proposes a multi-objective orthogonal opposition-based crow search algorithm (M2O-CSA) for solving large-scale multi-objective optimization problems (LSMOPs). In the M2O-CSA, a multi-orthogonal opposition strategy is employed to mitigate the conflicts among the convergence and distribution of solutions. First, two individuals are randomly chosen to undergo the crossover stage and then orthogonal array is presented to obtain nine individuals. Then individuals are used in the opposition stage to improve the diversity of solutions. The effectiveness of the proposed M2O-CSA is investigated by implementing it on different dimensions of multi-objective optimization problems (MOPs). The Pareto front solutions of these MOPs have various characteristics such as convex, non-convex and discrete. It is also applied to solve multi-objective design applications with distinctive features such as four bar truss (FBT) design, welded beam (WB) deign, disk brake (DB) design, and speed reduced (SR) design, where they involve different characteristics. In this context, a new decision making tool based on multi-objective optimization on the basis of ratio analysis (MOORA) technique is employed to help the designer for extracting the operating point as the best compromise or satisfactory solution to execute the candidate engineering design. Simulation results affirm that the proposed M2O-CSA works efficiently and effectively.
Article
Full-text available
Since the environment-friendly production has attracted extensive attention of many manufacturing enterprises, the energy consumption has become one of the core indices to evaluate production processes. Under this circumstance, the main purpose of this paper is to propose an efficient scheduling method for multi-objective shop floor multi-crane scheduling problems. In this research, the objectives of minimizing total weighted tardiness and total energy consumption are considered simultaneously. Owing to the NP-hard nature of the investigated problem, an improved decomposition-based 2-echelon multi-objective evolutionary algorithm with energy-efficient local search strategies (2-echelon iMOEA/D) is developed to solve the problem. The upper echelon optimizer of the proposed algorithm extends the advantages of computing resources allocation and adaptive neighborhood adjustment to accelerate the convergence speed, while the lower echelon optimizer utilizes energy-efficient local search strategies to realize deep optimization of the algorithm. The performance of the proposed method is compared with two other high-efficient multi-objective optimization algorithms. The computation results indicate that the proposed 2-echelon iMOEA/D achieves better performance both on solutions’ quality and diversity.
Article
Full-text available
Effective filter design plays an important role in signal processing applications. Multiple parameters must be considered to control the over-frequency response of the designed filter. In this study, a novel multi-objective approach is proposed for windowing finite impulse response (FIR) filter design. The windowing FIR filters are commonly used due to its linear phase property, frequency stability and easier implementation. However, windowing method can only control the cutting frequency of filter, and it suffers from the problem of insufficient control of the transition bandwidth, pass and stop band cutoff frequencies. Therefore, the window function was optimized using a novel multi-objective artificial bee colony (ABC) algorithm based on singular spectrum analysis (SSA) to eliminate these disadvantages of the windowing method. The proposed method was compared to three other multi-objective ABC variants. Novel SSA-based multi-objective approach yielded the best performance among four approaches. The proposed multi-objective approach that uses the SSA method has a significant advantage since it does not require user experience, it is not dependent on parameters, and there is no weight determination problem. Also, it does not have sorting and pooling stages that increase the cost of calculation. The obtained results were compared with the published literature studies. The SSA-based multi-objective approach offered better alternative to other literature techniques in terms of calculating the fitness function that deals with finding the most reasonable solution considering all error terms. Finally, the performance of the designed filter was tested on electroencephalography (EEG) signal. The EEG signal was decomposed successfully into subbands using proposed filter design approach. Based on numerical results of this study, the proposed filter provided the low-pass band and stop band ripple, and high stop band attenuation value of all, while having well enough performance.
Article
The quantity of waste electrical and electronic equipment (WEEE) is very large. WEEE not only occupies resources, but also easily pollutes the environment. The disassembly line is the most efficient way to address large-scale WEEE. How to improve disassembly profit and reduce energy consumption has become a significant and challenging research topic. However, the existing literature only considers the completely normal disassembly mode, ignoring the uncertainties such as corrosion and deformation of parts, and the evaluation system of the disassembly line cannot take into account both economic benefits and environmental impacts. Therefore, this paper introduces the destructive disassembly mode into the disassembly line and proposes a partial destructive disassembly line balancing model. The model aims to comprehensively optimize the number of stations, smoothness index, energy consumption, and disassembly profit. To obtain high-quality disassembly schemes, an improved genetic algorithm based on task precedence relationship is developed. Finally, the proposed model and method are applied to an engineering example of a television disassembly line. The performance of the proposed method is verified by comparing it with ant colony optimization, particle swarm optimization, artificial bee colony, and simulated annealing. The analysis of the disassembly schemes shows that the partial destructive mode can improve the disassembly profit and reduce energy consumption.
Article
Purpose This paper aims to investigate the scheduling and loading problems of tow trains for mixed-model assembly lines (MMALs). An in-plant milk-run delivery model has been formulated to minimize total line-side inventory for all stations over the planning horizon by specifying the departure time, parts quantity of each delivery and the destination station. Design/methodology/approach An immune clonal selection algorithm (ICSA) combined with neighborhood search (NS) and simulated annealing (SA) operators, which is called the NSICSA algorithm, is developed, possessing the global search ability of ICSA, the ability of SA for escaping local optimum and the deep search ability of NS to get better solutions. Findings The modifications have overcome the deficiency of insufficient local search and deepened the search depth of the original metaheuristic. Meanwhile, good approximate solutions are obtained in small-, medium- and large-scale instances. Furthermore, inventory peaks are in control according to computational results, proving the effectiveness of the mathematical model. Research limitations/implications This study works out only if there is no breakdown of tow trains. The current work contributes to the in-plant milk-run delivery scheduling for MMALs, and it can be modified to deal with similar part feeding problems. Originality/value The capacity limit of line-side inventory for workstations as well as no stock-outs rules are taken into account, and the scheduling and loading problems are solved satisfactorily for the part distribution of MMALs.
Article
Due to the increasing greenhouse gas emissions and the energy crisis, the manufacturing industry which is one of the most energy intensive sector is paying close attention to the improvement of environmental performance efficiency. Therefore, in this paper the automated assembly line is balanced in a sustainable way which aims to optimize a green manufacturing objective (the total energy consumption) and a productivity-related objective (similar working load) simultaneously. A comprehensive total energy consumption of each processing stage was analyzed and modeled. To make the model more practical, a sequence-based changeover time and robots with different efficiencies and energy consuming rates are considered and optimized. To properly solve the problem, the proposed novel optimal solution takes the well-known MOEA/D as a base and incorporates a well-designed coding scheme and a problem-specific local search mechanism. Computational experiments are conducted to evaluated each improving strategies of the algorithm and its superiority over two other high-performing multi-objective optimization methods. The model allows decision makers to select more sustainable assembly operations based on their decision impacts in both productivity and energy-saving.
Article
Since greening scheduling is arousing increasing attention from many manufacturing enterprises, this paper focuses on a flexible job shop greening scheduling problem with crane transportation (FJSGSP-CT). Distinguished from the traditional scheduling model which merely concentrates on machining processes, FJSGSP-CT takes the comprehensive effect of machining and crane transportation processes into consideration. Due to the NP-hard nature of the problem, an efficient hybrid algorithm, particle filter and Levy flight-based decomposed multi-objective evolution hybridized with particle swarm (PLMEAPS), is developed to find feasible solutions. The proposed PLMEAPS benefits from the synergy of decomposed multi-objective evolutionary algorithm (MOEA/D) and particle swarm optimization (PSO). Particle filter and Levy flights are then creatively fused into the framework of PLMEAPS to enhance the computational performance of the algorithm. The introduction of particle filter enriches the diversity of the population and makes it possible to predict the near optimal solutions at each iteration, and the combination of Levy flights has beneficial effect on escaping from local optimum and accelerating convergence speed. The performance of the proposed PLMEAPS is evaluated by comparing with two other high-performing intelligent optimization algorithms, the multi-objective genetic local search (MOGLS) and the multi-objective grey wolf optimizer (MOGWO). The computational results reveal that the proposed PLMEAPS outperforms the other two algorithms both in solutions’ quality and convergence rate when solving FJSGSP-CT.
Article
The paradigms of sustainability and circular economy have represented separate streams of academic literature but there is a growing realization that these two paradigms may have a mutually-constitutive relationship. Particularly, the relationship among the two notions in the context of supply chains remains unexplored and this is the focus of this research. We draw on the organizational sense making literature to identify the organizational enablers of circular supply chains and their relationships with the environmental performance of supply chains. Data was collected from various supply chains within the United Arab Emirates (UAE). A structural equation modelling (SEM) approach was adopted to test the hypothesis derived from a systematic review of the literature. Originality of this work stems from the conceptualisation and validation of a framework for circular supply chains and sustainable performance as a combination of process facilitators and a persuasive organizational narrative that enables organizations to embrace the circular economy practices. The validated framework has implications for both academia and the industry because of its emphasis on the joint effects of a) the discursive ability of organizational actors to articulate a paradigm shift towards circular supply chains b) the process facilitators comprising of actions and practices that enable circular supply chains.
Article
Purpose- Optimizing material handling within the factory is one of the key problems of modern assembly line systems. This paper focuses on simultaneously balancing a robotic assembly line and scheduling of material handling required for the operation of such a system, a topic that has received limited attention in academia. Manufacturing industries focuses on full autonomy due to the rapid advancements in different elements of Industry 4.0 such as internet of things, big data and cloud computing. In smart assembly systems, this autonomy aims at the integration of automated material handling equipment like automated guided vehicles (AGVs) to robotic assembly line systems to ensure a reliable and flexible production system. Design/methodology/approach- This paper tackles the problem of designing a balanced robotic assembly lines and scheduling of automated guided vehicles to feed materials to these lines such that the cycle time and total tardiness of the assembly system are minimized. Due to the combination of two well-known complex problems: line balancing and material handling, a heuristic and metaheuristic-based integrated decision approach is proposed. Findings- Detailed computational study demonstrates how integrated decision approach can serve as an efficient managerial tool in designing/redesigning assembly line systems and support automated transportation infrastructure. Originality/value- This work is beneficial for the production managers in understanding the main decisional steps involved in the designing/redesigning of smart assembly systems and providing guidelines in decision making. Moreover, this study explores the material distribution scheduling problems in assembly systems, which is not yet largely explored in the literature.