A heuristic for assembly and disassembly line balancing

Abstract

This paper deals with simple assembly/disassembly line balancing problems. We developed a heuristic algorithm for estimating the minimum number of workstations at a given cycle time. Although heuristic, the algorithm enables the search for exact solutions of balancing problems of intermediate size. This has been demonstrated by applying the method to task precedence graphs composed of up to 25 tasks. Not only the complete set of solutions with the minimum number of workstations was generated by the algorithm, but it also enabled the detection of the best solution with regard to the smoothness index, i.e. the optimally balanced task assignment. This has been obtained by reduction of the size of the search space via appropriate classification in sets of equivalent partial assignments were generated in the course of the calculation. We demonstrated the method on the basis of two different task precedence graphs that have been selected from the literature.