Batch-model assembly line balancing: A multiattribute decision making approach

Traditionally, assembly line balancing involves determining the number of workstations using a single criterion method like balance delay, production cost or number of workstations minimization under certain constraints. The cycle time, determined from the demand of the product, is taken as an input parameter. This approach may not be well-suited for a batch-model assembly line under frequent changeover situation because of the desirability to reduce changeover time. In this paper, a multiattribute-based approach is developed to determine the number of workstations. At first, a set of feasible number of workstations which are balanced for each product model are generated. A procedure is then developed to compute the changeover time for each configuration (number of workstation), and finally, a multiattribute evaluation model is developed to select the number of workstations considering product rate, variety, minimum distance moved, division of labor and quality using the analytic hierarchy process and simulation. The methodology is then applied to a real-life batch-model assembly line for printing calculators.