Minimizing production costs for a robotic assembly system

The objective of this study is to minimize the expected present worth of the production costs incurred over the operational life of a robotic assembly system that is integrated with an Automatic Storage/Retrieval System (AS/RS). Production costs include inventory cost and capital cost of equipment. Inventory cost consists of ordering, holding, and lost-production costs; and all of these costs depend on the scheduling policy for the assembly robots as well as the inventory policy for the AS/RS. Capital cost of equipment depends on the number of depalletizer robots and the number of assembly robots. To identify the minimum-cost design for a certain automotive assembly operation from a given set of alternative system configurations, the authors present a simulation experiment in which independent replications of each alternative are controlled by a statistical ranking-and-selection procedure that has been adapted to simulation.