The effect of learning on the operations of mixed-model assembly lines

The common approach to balancing mixed-model assembly lines assumes that the line operators are well trained and that the learning effect is negligible. The assumption is that the line operates in steady state over a long period of time. Time-based competition and frequent design changes in many products make this assumption incorrect, and the effect of learning on mixed-model lines should not be neglected. The authors defined start-up period and developed a model for the line design during start-up. It can be used to evaluate a proposed line design or to develop a feasible line design and to estimate its cost. This proposed model integrates mixed-model learning curves with aggregate planning under learning and a mixed-model line design into a comprehensive framework designed to minimize the total cost of the line during the start-up period.