• Journal of Institute of Control, Robotics and Systems
• /
• v.1 no.2
• /
• pp.112-118
• /
• 1995

In designing assembly lines, it is required that the lines should not only meet the demand of the product, but also minimize the assembly cost associated with the line. For such a purpose, numerous research efforts have been made on either the assembly sequence generation or the assembly line balancing. However, the works dealing with both the research problems have been seldom reported in literature. When assembly sequences are generated without consideration of line balancing, additional cost may be incurred, because the sequences may not guarantee the minimum number of workstations. Therefore, it is essential to consider line balancing in the generation of cost-effective assembly sequences. To incorporate the two research problems into one, this paper treats a single-model and deterministic (SMD) assembly line balancing (ALB) problem, and proposes a new method for generating line-balanced robotic assembly sequences by using a simulated annealing. In this method, an energy function is derived in consideration of the satisfaction of assembly constraints, and the minimization of both the assembly cost and the idle time. Then, the energy function is iteratively minimized and occasionally perturbed by the simulated annealing. When no further change in energy occurs, an assembly sequence with consideration of line balancing is finally found. To show the effectiveness of the proposed scheme, a case study for an electrical relay is presented.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.3 no.3
• /
• pp.35-39
• /
• 1980

Although the product line produces a large volume of goods in a relatively short time, once the product line is established there are numerous problems that arise in connection with this product line. One of these problems is the problem of balancing operations or stations in terms of equal times and in terms of the times required to meet the desered rate of production. The objective of line balancing is minimizing the idle time on the line for all combinations of work stations subject to certain restrictions. In general, there are two types of line-balancing situations : (1) assembly line balancing and (2) fabrication line balancing. Two approaches to the assembly line balancing problem have been used. The first assumes a filed cycle time and find the optimum number of work stations. The second approach to the assembly line balancing problem assumes the number of work stations to be fixed and systematically coverages on a solution which minimizes the total delay time by minimizing the cycle time. Here the cycle time is determined by the longest station time. In this paper, by using the second approach method, a general mathematical model, problem solutions, and computer program for the assembly line balancing problem is presented. Data used is obtained from the company which has been confronted with many problems arising in connection with their assembly line.

• Journal of the Korean Society for Precision Engineering
• /
• v.18 no.8
• /
• pp.129-138
• /
• 2001

The paper presents an implementation procedure of assembly line for ABS motor, which is composed of four subassemblies-yoke, grommet, housing and armature. The characteristics of ABS motor and its assembly processes are analysed, and the automation possibility of each process is examined in order to decrease assembly time. The assembly machines and facilities are then selected for automatic assembly, and the layout of the selected facilities is determined. Finally, task allocation of each worker is achieved by assembly line balancing to increase assembly productivity and efficiency. The line efficiency is also analyzed using simulation.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.18 no.2
• /
• pp.1-22
• /
• 1993

This paper deals with the problem of mixed model assembly line balancing. In mixed model assembly lines, tsks should be assigned to stations in such a manner that all stations have approximately the same amount of work on a production cycle basis. Further in balancing assembly lines, the related tasks, the performing task side and the team tasks should be considered to improve work methods, to give more job satisfaction to workers, and to allow greater flexibility in the design of assembly lines. In this paper, the heuristic dispatch assignment rule is developed to assign evenly tasks of each model to all stations. The heuristic method based on the assignment rule developed is presented for mixed model assembly line balancing with the considerations of the related tasks, the performing task side, and the team tasks. The proposed method is analyzed, and compared with other methods for line balancing.

• 제어로봇시스템학회:학술대회논문집
• /
• 1993.10a
• /
• pp.1123-1128
• /
• 1993

In this paper, utilizing the line balancing algorithm proposed to deal with various situations of automated assembly line, the optimal solution can be derived by the branch and bound method of analysis. By the application of line balancing algorithm to telephone assembly line, thoughput is improved by 3.38%. Therefore, in the proposed line, blicking phenomena were reduced and smooth line-flow was achieved, and uniform distribution of utilization rate of each machine is obtained.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.28 no.3
• /
• pp.98-108
• /
• 2005

The assembly line balancing problem has been focused by many research works because the efficient management of the assembly line might influence not only the quality of the products but also the working conditions for the workers. This paper deals with U-shape mixed-model assembly line balancing and considers both the processing time and the physical workloads. We suggest the goal programming approach for this situation and to overcome some difficulties of finding optimal solution, we adopt the genetic algorithm that is one of the most promising solution techniques. We tested several test problems and present the results that indicate some improvement for the line balancing as well as the stable performance of the algorithm.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.18 no.2
• /
• pp.339-350
• /
• 1994

This paper presents a method for automatic generation of line balanced assembly sequences based on disassemblability and proposes a method of evaluating an assembly work time using neural networks. Since a line balancing problem in flexible assembly system requires a sophisticated planning method, reasoning about line balanced assembly sequences is an important field of concern for planning assembly lay-out. For the efficient inference of line balanced assembly sequences, many works have been reported on how to evaluate an assembly work time at each work station. However, most of them have some limitations in that they use cumbersome user query or approximated assembly work time data without considering assembly conditions. To overcome such criticism, this paper proposes a new approach to mathematically verify assembly conditions based on disassemblability. Based upon the results, we present a method of evaluating assembly work time using neural networks. The proposed method provides an effective means of solving the line balancing problem and gives a design guidance of planning assembly lay-out in flexible assembly application. An example study is given to illustrate the concepts and procedure of the proposed scheme.

• IE interfaces
• /
• v.22 no.2
• /
• pp.144-152
• /
• 2009

Assembly line has been recognized as an efficient production system in mass production. However, the recent production environment characterized as mass customization urges production managers to transform a long assembly line to a number of short assembly cells. To maximize the utilization of resources in an assembly cell, it is important to have the line balanced. This paper presents a bucket brigade-based assembly cell. Bucket brigade is a way of coordinating workers who progressively perform a set of assembly operations on a flow line. Each worker follows a simple rule: perform assembly operations on a product until the next worker downstream takes it over; then go back to the previous worker upstream to take over a new assembly job. In this way, the line balances itself. The bucket brigade assembly cell is analyzed and compared with traditional assembly lines and general assembly cells. The paper also discusses some prerequisite requirements and limitations when the bucket brigade assembly cells are employed.

• IE interfaces
• /
• v.12 no.1
• /
• pp.132-142
• /
• 1999

Two-sided (left- and right-sided) assembly lines in practice can provide several advantages over one-sided lines in terms of the required line length, throughput time, cost of tools and fixtures, and so on. This paper considers two-sided assembly line balancing with the objective of minimizing line length. The balancing problem is more complicated than that of one-sided lines due to sequence-dependency of tasks assigned to a pair of directly facing workstations. This paper shows how genetic algorithm can be used to solve two-sided assembly line balancing. For this, an encoding and a decoding method suitable to the problem are presented. Proper genetic operators and an evalutation function are also employed. Extensive computational experiments are carried out to show the efficacy of the proposed algorithm. The results show that the algorithm is viable and promising in solution quality and computation time.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2004.05a
• /
• pp.425-428
• /
• 2004

Flexible assembly line (FAL) is a production system that assembles various parts in unidirectional flow line with many constraints and manufacturing flexibilities. In this research we deal with a FAL balancing problem with the objective of minimizing the maximum workload allocated to the stations. However, almost all the existing researches do not appropriately consider various constraints due to the problem complexity. Therefore, this thesis addresses a balancing problem of FAL with many constraints and manufacturing flexibilities, unlike the previous researches. To solve this problem we use a genetic algorithm (GA). To apply GA to FAL, we suggest a genetic representation suitable for FAL balancing and devise evaluation method for individual's fitness and genetic operators specific to the problem, including efficient repair method for preserving solution feasibility. The experimental results are reported.