Balancing collaborative human–robot assembly lines to optimise cycle time and ergonomic risk

2021 ◽  
pp. 1-23
Author(s):  
Kathryn E. Stecke ◽  
Mahdi Mokhtarzadeh
Keyword(s):  
Cycle Time ◽  
Assembly Lines ◽  
Ergonomic Risk

An adaptive BPSO algorithm for multi-skilled workers assignment problem in aircraft assembly lines

2015 ◽  
Vol 35 (4) ◽  
pp. 317-328 ◽  
Author(s):  
Bo Xin ◽  
Yuan Li ◽  
Jianfeng Yu ◽  
Jie Zhang
Keyword(s):  
Cycle Time ◽  
Assignment Problem ◽  
Stability And Convergence ◽  
Binary Particle Swarm Optimization ◽  
Assembly Lines ◽  
Skilled Workers ◽  
Time Model ◽  
Content Type ◽  
Aircraft Assembly ◽  
Human Cost

Purpose – The purpose of this paper is to investigate the multi-skilled workers assignment problem in complex assembly systems such as aircraft assembly lines. An adaptive binary particle swarm optimization (A-BPSO) algorithm is proposed, which is used to balance the workload of both assembly stations and processes and to minimize the human cost. Design/methodology/approach – Firstly, a cycle time model considering the cooperation of multi-skilled workers is constructed. This model provides a quantitative description of the relationship between the cycle time and multi-skilled workers by means of revising the standard learning curve with the “Partition-And-Accumulate” method. Then, to improve the accuracy and stability of the current heuristic algorithms, an A-BPSO algorithm that suits for the discrete optimization problems is proposed to assign multi-skilled workers to assembly stations and processes based on modified sigmoid limiting function. Findings – The proposed method has been successfully applied to a practical case, and the result justifies its advantage as well as adaptability to both theory and engineering application. Originality/value – A novel cycle time model considering cooperation of multi-skilled workers is constructed so that the calculation results of cycle time are more accurate and closer to reality. An A-BPSO algorithm is proposed to improve the stability and convergence in dealing with the problems with higher dimensional search space. This research can be used by the project managers and dispatchers on assembly field.

scholarly journals Maximizing the robustness for simple assembly lines with fixed cycle time and limited number of workstations

2016 ◽  
Vol 208 ◽  
pp. 123-136 ◽  
Author(s):  
André Rossi ◽  
Evgeny Gurevsky ◽  
Olga Battaïa ◽  
Alexandre Dolgui
Keyword(s):  
Cycle Time ◽  
Assembly Lines ◽  
Simple Assembly

Effective Cycle Time: A Real World Balancing Index for Paced Assembly Lines

2010 ◽  
Vol 14 (5) ◽  
pp. 431-441
Author(s):  
Konstantinos N. Genikomsakis ◽  
◽  
Vassilios D. Tourassis
Keyword(s):  
Performance Measures ◽  
Cycle Time ◽  
Assembly Line ◽  
Assembly Line Balancing ◽  
Line Balancing ◽  
Research Trend ◽  
Time Variability ◽  
Assembly Lines ◽  
Simulation Experiments

Assembly Line Balancing (ALB) aims at optimally assigning the work elements required to assemble a product to an ordered sequence of workstations, while satisfying precedence constraints. Notwithstanding the advances and developments in ALB over the years, recent and thorough surveys on this field reveal that only a small percentage of companies employ ALB procedures to configure their assembly lines. This paradox may be attributed, to some extent, to the fact that ALB is addressed mostly under ideal conditions. Despite the time variability inherent in manufacturing tasks, there is a strong research trend towards designing and implementing algorithms that consider ALB on a deterministic basis and focus on the optimality of the proposed task assignments according to existing ALB performance measures. In this paper, the need to assess the performance of the proposed solutions of various algorithms in the literature is corroborated through simulation experiments on a benchmark ALB problem under more realistic conditions. A novel ALB index, namely the Effective Cycle Time, ECT, is proposed to assess the quality of alternative assembly line configurations in paced assembly lines operating under task times variations.

scholarly journals Mixed integer linear programming models for minimizing ergonomic risk dispersion in an assembly line at the Nissan Barcelona factory

2018 ◽  
pp. 72-89 ◽  
Author(s):  
Joaquín Bautista-Valhondo ◽  
Rocío Alfaro-Pozo
Keyword(s):  
Assembly Line ◽  
Mixed Model ◽  
Assembly Line Balancing ◽  
Mixed Integer ◽  
Assembly Lines ◽  
Absolute Deviation ◽  
Mixed Model Assembly Lines ◽  
Average Maximum ◽  
Ergonomic Risk

We present a variant of the approach to the assembly line balancing problems, with the aim of reducing the ergonomic risk for operators of mixed-model assembly lines (MILP-3). Specifically, the MILP-3 model is focused on minimizing the average range between ergonomic risk values of workstations. Using a case study from Nissan’s plant in Barcelona, not only are the differences between levels of ergonomic risk of stations reduced, but we attempt to reduce the average maximum ergonomic risk of the assembly line. The new model is compared with two others, MILP-1 and MILP-2, which minimize the average maximum ergonomic risk and the average absolute deviation of the risks, respectively.

A novel optimal method of robotic weld assembly line balancing problems with changeover times: a case study

2018 ◽  
Vol 38 (4) ◽  
pp. 376-386 ◽  
Author(s):  
Binghai Zhou ◽  
Qiong Wu
Keyword(s):  
Local Search ◽  
Cycle Time ◽  
Assembly Line ◽  
Research Work ◽  
Assembly Line Balancing ◽  
Line Balancing ◽  
Assembly Lines ◽  
Optimal Method ◽  
Content Type ◽  
Changeover Times

PurposeThe balancing of robotic weld assembly lines has a significant influence on achievable production efficiency. This paper aims to investigate the most suitable way to assign both assembly tasks and type of robots to every workstation, and present an optimal method of robotic weld assembly line balancing (ALB) problems with the additional concern of changeover times. An industrial case of a robotic weld assembly line problem is investigated with an objective of minimizing cycle time of workstations.Design/methodology/approachThis research proposes an optimal method for balancing robotic weld assembly lines. To solve the problem, a low bound of cycle time of workstations is built, and on account of the non-deterministic polynomial-time (NP)-hard nature of ALB problem (ALBP), a genetic algorithm (GA) with the mechanism of simulated annealing (SA), as well as self-adaption procedure, was proposed to overcome the inferior capability of GA in aspect of local search.FindingsTheory analysis and simulation experiments on an industrial case of a car body welding assembly line are conducted in this paper. Satisfactory results show that the performance of GA is enhanced owing to the mechanism of SA, and the proposed method can efficiently solve the real-world size case of robotic weld ALBPs with changeover times.Research limitations/implicationsThe additional consideration of tool changing has very realistic significance in manufacturing. Furthermore, this research work could be modified and applied to other ALBPs, such as worker ALBPs considering tool-changeover times.Originality/valueFor the first time in the robotic weld ALBPs, the fixtures’ (tools’) changeover times are considered. Furthermore, a mathematical model with an objective function of minimizing cycle time of workstations was developed. To solve the proposed problem, a GA with the mechanism of SA was put forth to overcome the inferior capability of GA in the aspect of local search.

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