Joint design for assembly and disassembly lines balancing problem

This thesis focuses on disassembly system design in the areas of line balancing, throughput performance evaluation and unified assembly/disassembly line balancing problem. Firstly, disassembly line balancing problem (DLB) is analyzed and a beam search based approach for the problem is proposed. The results of proposed algorithm are compared with the optimal solutions of well-known real cases and generated test problems. Secondly, a new mathematical model is developed for DLB problem with resource-constrained case. The objective is to minimize the number of resources and workstations under a given cycle time. Thirdly, a new balancing problem for unified line design, called parallel assembly and disassembly line system, is defined and solution approaches are presented. The proposed design consists of two separate dedicated lines, one for assembly and another for disassembly, on which products and parts move reversely. Due to assembly and disassembly of the same product on lines, it is considered that some assembly and disassembly tasks are similar. Thus, an integer linear programming model and heuristic approach based on ant colony optimization for solving the balancing problem is improved. Minimum the number of workstations is aimed while assigning the similar assembly and disassembly tasks to the same or close workstation