Workload smoothing in two-sided assembly lines

2018 ◽  
Vol 38 (1) ◽  
pp. 51-56 ◽  
Author(s):  
Xiaofeng Hu ◽  
Chunaxun Wu
Keyword(s):  
Assembly Line ◽  
Assembly Line Balancing ◽  
Idle Time ◽  
Line Balancing ◽  
Assembly Lines ◽  
Absolute Deviation ◽  
Content Type ◽  
Smoothness Index ◽  
Assembly Line Balancing Problem ◽  
New Criteria

Purpose The purpose of this paper is to define new criteria for measuring workload smoothness of two-sided assembly lines and propose an algorithm to solve a two-sided assembly line balancing problem focusing on distributing the idle time and the workload as evenly as possible among the workstations. Design/methodology/approach This paper points out that the mean absolute deviation (MAD) and the smoothness index (SI) used to measure the workload smoothing in one-sided assembly lines are both inappropriate to evaluate the workload balance among workstations in two-sided assembly lines, as the idle time occur at the beginning and in the middle of a cycle within workstations. Then, the finish-time-based SI and MAD (FSI and FMAD) are defined, and a heuristic procedure based on the core mechanism of Moodie and Young method is proposed to smooth the assembly workload in two-sided assembly lines. Findings The computational results indicate that the proposed heuristic algorithm combined with the FMAD is effective in distributing the idle time and the workload among workstations as evenly as possible in two-sided assembly lines. Practical implications The two-sided assembly line balancing problem with the objective of the line efficiency can be effectively solved by the proposed approach. Originality/value The FMAD is proposed to effectively improve the workload smoothing in two-sided assembly lines.

Multi-manned assembly line balancing problem with balanced load density

2015 ◽  
Vol 35 (1) ◽  
pp. 137-142 ◽  
Author(s):  
Hamid Yilmaz ◽  
Mustafa Yilmaz
Keyword(s):  
Mathematical Model ◽  
Assembly Line ◽  
Assembly Line Balancing ◽  
Line Balancing ◽  
Assembly Lines ◽  
Content Type ◽  
Task Load ◽  
Balance Task ◽  
Assembly Line Balancing Problem ◽  
First Time

Purpose – The purpose of this paper is balancing multi-manned assembly lines with load-balancing constraints in addition to conventional ones Most research works about the multi-manned assembly line balancing problems are focused on the conventional industrial measures that minimize total number of workers, number of multi-manned workstations or both. Design/methodology/approach – This paper provides a remedial constraint for the model to balance task load density for each worker in workstations. Findings – Comparisons between the proposed mathematical model and the existing multi-manned mathematical model show a quite promising better task load density performance for the proposed approach. Originality/value – In this paper, a mathematical model that combines the minimization of multi-manned stations, worker numbers and difference of task load density of workers is proposed for the first time.

scholarly journals A Novel Assembly Line Balancing Method Based on PSO Algorithm

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Xiaomei Hu ◽  
Yangyang Zhang ◽  
Ning Zeng ◽  
Dong Wang
Keyword(s):  
Manufacturing System ◽  
Assembly Line ◽  
Assembly Line Balancing ◽  
Pso Algorithm ◽  
Optimization Method ◽  
Line Balancing ◽  
Assembly Lines ◽  
Smoothness Index ◽  
Takt Time ◽  
Assembly Line Balancing Problem

Assembly line is widely used in manufacturing system. Assembly line balancing problem is a crucial question during design and management of assembly lines since it directly affects the productivity of the whole manufacturing system. The model of assembly line balancing problem is put forward and a general optimization method is proposed. The key data on assembly line balancing problem is confirmed, and the precedence relations diagram is described. A double objective optimization model based on takt time and smoothness index is built, and balance optimization scheme based on PSO algorithm is proposed. Through the simulation experiments of examples, the feasibility and validity of the assembly line balancing method based on PSO algorithm is proved.

Parallel two-sided assembly line balancing with tools and tasks sharing

2019 ◽  
Vol 40 (6) ◽  
pp. 833-846
Author(s):  
Ashish Yadav ◽  
Ramawatar Kulhary ◽  
Rupesh Nishad ◽  
Sunil Agrawal
Keyword(s):  
Assembly Line ◽  
Assembly Line Balancing ◽  
Solution Procedure ◽  
Performance Measure ◽  
Line Balancing ◽  
Benchmark Problems ◽  
Test Problems ◽  
Assembly Lines ◽  
Content Type ◽  
Assembly Line Balancing Problem

Purpose Parallel two-sided assembly lines are usually designed to produce large-sized products such as trucks and buses. In parallel two-sided assembly lines, both left and right sides of the line are used for manufacturing one or more products on two or more assembly lines located parallel to each other. The purpose of this paper is to develop a new mathematical model for the parallel two-sided assembly line balancing problem that helps to evaluate and validate the balancing operations of the machines such as removal of tools and fixtures and reallocating the operators. Design/methodology/approach The proposed approach is explained with the help of an example problem. In all, 22 test problems are formed using the benchmark problems P9, P12, P16 and P24. The results obtained are compared among approaches of the task(s) shared, tool(s) shared and both tool(s) and task(s) shared for effect on efficiency as the performance measure. The solution presented here follows the exact solution procedure that is solved by Lingo 16 solver. Findings Based on the experiments, line efficiency decreases when only tools are shared and increases when only tasks are shared. Results indicate that by sharing tasks and tools together, better line efficiency is obtained with less cost of tools and fixtures. Practical implications According to the industrial aspect, the result of the study can be beneficial for assembly of the products, where tools and tasks are shared between parallel workstations of two or more parallel lines. Originality/value According to the author’s best knowledge, this paper is the first to address the tools and tasks sharing between any pair of parallel workstations.

A multi-manned assembly line balancing problem with classified teams: a new approach

2016 ◽  
Vol 36 (1) ◽  
pp. 51-59 ◽  
Author(s):  
Hamid Yilmaz ◽  
Mustafa Yilmaz
Keyword(s):  
Design Methodology ◽  
Assembly Line ◽  
Assembly Line Balancing ◽  
Line Balancing ◽  
Test Problems ◽  
New Approach ◽  
Content Type ◽  
Line Test ◽  
Assembly Line Balancing Problem ◽  
First Time

Purpose – Within team-oriented approaches, tasks are assigned to teams before being assigned to workstations as a reality of industry. So it becomes clear, which workers assemble which tasks. Design/methodology/approach – Team numbers of the assembly line can increase with the number of tasks, but at the same time, due to physical situations of the stations, there will be limitations of maximum working team numbers in a station. For this purpose, heuristic assembly line balancing (ALB) procedure is used and mathematical model is developed for the problem. Findings – Well-known assembly line test problems widely used in the literature are solved to indicate the effectiveness and applicability of the proposed approach in practice. Originality/value – This paper draws attention to ALB problem in which workers have been assigned to teams in advance due to the need for specialized skills or equipment on the line for the first time.

An immune genetic algorithm for simple assembly line balancing problem of type 1

2019 ◽  
Vol 39 (1) ◽  
pp. 113-123 ◽  
Author(s):  
Han-ye Zhang
Keyword(s):  
Genetic Algorithm ◽  
Assembly Line ◽  
Assembly Line Balancing ◽  
Line Balancing ◽  
Immune Genetic Algorithm ◽  
Content Type ◽  
Assembly Line Balancing Problem ◽  
Simple Assembly ◽  
First Time

Purpose The purpose of this study is to develop an immune genetic algorithm (IGA) to solve the simple assembly line balancing problem of type 1 (SALBP-1). The objective is to minimize the number of workstations and workstation load for a given cycle time of the assembly line. Design/methodology/approach This paper develops a new solution method for SALBP-1, and a user-defined function named ψ(·) is proposed to convert all the individuals to satisfy the precedence relationships during the operation of IGA. Findings Computational experiments suggest that the proposed method is efficient. Originality/value An IGA is proposed to solve the SALBP-1 for the first time.

Study on Aircraft Assembly Line Balancing Problem Based on Mobile Workers

2016 ◽  
Author(s):  
Jie Zhang ◽  
Bo Xin ◽  
Pan Wang
Keyword(s):  
Assembly Line ◽  
Particle Swarm ◽  
Assembly Line Balancing ◽  
Line Balancing ◽  
Stability And Convergence ◽  
Particle Swarm Algorithm ◽  
Binary Particle Swarm Optimization ◽  
Assembly Lines ◽  
Aircraft Assembly ◽  
Assembly Line Balancing Problem

In order to improve the balance and load equilibrium of aircraft assembly lines, and to enhance the management of on-site resources, a Type-E balancing method was proposed based on the mobile operation of assembly personnel in the aircraft assembly line. This method was aimed to minimize the smoothness index of the overall assembly line and each assembly station, and also to minimize manpower costs. First, a model of personnel flow and an assembly line balancing model were constructed based on the characteristics of aircraft assembly lines. Next, an Accelerated Binary Particle Swarm Optimization (ABPSO) based on improved sig function was designed in order to improve the original stability and convergence of the standard binary particle swarm algorithm. Finally, the validity of the method was verified with a real fuselage assembly line and the results show the effectiveness.

An improved immune clonal selection algorithm for bi-objective robotic assemble line balancing problems considering time and space constraints

2019 ◽  
Vol 36 (6) ◽  
pp. 1868-1892 ◽  
Author(s):  
Binghai Zhou ◽  
Qiong Wu
Keyword(s):  
Assembly Line ◽  
Clonal Selection ◽  
Assembly Line Balancing ◽  
Robotic Assembly ◽  
Line Balancing ◽  
Clonal Selection Algorithm ◽  
Selection Algorithm ◽  
Assembly Lines ◽  
Content Type ◽  
Multi Objective

Purpose The extensive applications of the industrial robots have made the optimization of assembly lines more complicated. The purpose of this paper is to develop a balancing method of both workstation time and station area to improve the efficiency and productivity of the robotic assembly lines. A tradeoff was made between two conflicting objective functions, minimizing the number of workstations and minimizing the area of each workstation. Design/methodology/approach This research proposes an optimal method for balancing robotic assembly lines with space consideration and reducing robot changeover and area for tools and fixtures to further minimize assembly line area and cycle time. Due to the NP-hard nature of the considered problem, an improved multi-objective immune clonal selection algorithm is proposed to solve this constrained multi-objective optimization problem, and a special coding scheme is designed for the problem. To enhance the performance of the algorithm, several strategies including elite strategy and global search are introduced. Findings A set of instances of different problem scales are optimized and the results are compared with two other high-performing multi-objective algorithms to evaluate the efficiency and superiority of the proposed algorithm. It is found that the proposed method can efficiently solve the real-world size case of time and space robotic assembly line balancing problems. Originality/value For the first time in the robotic assembly line balancing problems, an assignment-based tool area and a sequence-based changeover time are took into consideration. Furthermore, a mathematical model with bi-objective functions of minimizing the number of workstations and area of each station was developed. To solve the proposed problem, an improved multi-objective immune clonal selection algorithm was proposed and a special coding scheme is designed.

Balancing of parallel U-shaped assembly lines with a heuristic algorithm based on bidirectional priority values

2021 ◽  
pp. 1063293X2110655
Author(s):  
Yuling Jiao ◽  
Xue Deng ◽  
Mingjuan Li ◽  
Xiaocui Xing ◽  
Binjie Xu
Keyword(s):  
Mathematical Model ◽  
Heuristic Algorithm ◽  
Assembly Line ◽  
Assembly Line Balancing ◽  
Line Balancing ◽  
Assembly Lines ◽  
Line System ◽  
Assembly Line Balancing Problem ◽  
The Mathematical Model ◽  
Better Than

Aiming at improving assembly line efficiency and flexibility, a balancing method of parallel U-shaped assembly line system is proposed. Based on the improved product priority diagram, the bidirectional priority value formula is obtained. Then, assembly lines are partitioned into z-q partitions and workstations are defined. After that, the mathematical model of the parallel U-shaped assembly line balancing problem is established. A heuristic algorithm based on bidirectional priority values is used to solve explanatory examples and test examples. It can be seen from the results and the effect indicators of the assembly line balancing problem that the heuristic algorithm is suitable for large balancing problems. The proposed method has higher calculation accuracy and shorter calculation time. The balancing effect of the parallel U-shaped assembly line is better than that of single U-shaped assembly line, which verifies the superiority of the parallel U-type assembly line and effectiveness of the proposed method. It provides a theoretical and practical reference for parallel U-type assembly line balancing problem.

Robust optimization of resource-constrained assembly line balancing problems with uncertain operation times

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Wenrui Jin ◽  
Zhaoxu He ◽  
Qiong Wu
Keyword(s):  
Optimization Algorithm ◽  
Assembly Line ◽  
Assembly Line Balancing ◽  
Whale Optimization Algorithm ◽  
Line Balancing ◽  
Resource Constrained ◽  
Content Type ◽  
Whale Optimization ◽  
Minmax Regret ◽  
Assembly Line Balancing Problem

PurposeDue to the market trend of low-volume and high-variety, the manufacturing industry is paying close attention to improve the ability to hedge against variability. Therefore, in this paper the assembly line with limited resources is balanced in a robust way that has good performance under all possible scenarios. The proposed model allows decision makers to minimize a posteriori regret of the selected choice and hedge against the high cost caused by variability.Design/methodology/approachA generalized resource-constrained assembly line balancing problem (GRCALBP) with an interval data of task times is modeled and the objective is to find an assignment of tasks and resources to the workstations such that the maximum regret among all the possible scenarios is minimized. To properly solve the problem, the regret evaluation, an exact solution method and an enhanced meta-heuristic algorithm, Whale Optimization Algorithm, are proposed and analyzed. A problem-specific coding scheme and search mechanisms are incorporated.FindingsTheory analysis and computational experiments are conducted to evaluated the proposed methods and their superiority. Satisfactory results show that the constraint generation technique-based exact method can efficiently solve instances of moderate size to optimality, and the performance of WOA is enhanced due to the modified searching strategy.Originality/valueFor the first time a minmax regret model is considered in a resource-constrained assembly line balancing problem. The traditional Whale Optimization Algorithm is modified to overcome the inferior capability and applied in discrete and constrained assembly line balancing problems.

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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