Operation-sequence-based approach for designing cellular manufacturing systems

Abstract

This thesis considers these cell formation problems considering two configuration types of cell manufacturing system including flow line cell system and fabrication cell system of job-shop type. A flow line cell system is considered in chapters 2 and 3, and a fabrication cell system of job-shop type is considered in chapter 4. This thesis investigates the proposed problems from the motivation of gaining some underlying scheme and insight into any effective management of complex manufacturing systems and any effective control over various production parameters. In chapter 2, a cost model is considered for a U-shaped manufacturing cell formation which incorporates a required number of machines and various material flows together under multi-part multi-cell environment. The model is required to satisfy both the specified operation sequence of each part and the total part demand volume which are needed to derive material handling cost in U-shaped flow line cells. In the model, several other cost-incurring factors including set-up for batch change-over, processing time for operations of each part, and machine failures are also considered in association with processing load and capacity of each cell. The problem is characterized as a NP-hard problem. Therefore, in order to find a good solution efficiently, two greedy-type heuristic algorithms including a single-combining algorithm and a double- combining algorithm are proposed. For the heuristic solution algorithms, three schemes are proposed : a scheme for computing the utilization ratio subject to the processing time of each cell, a scheme for determining the machine sequence in each U-shaped cell and a scheme for searching the solution by using combining method. Both the algorithms are derived by using the process of combining the cells and tested for their efficiencies with various numerical problems Chapter 3 considers a problem of designing a flow line independent-cell system where each machine can treat multip...