General Economic Order Quantity Model for Lot Sizing with Quality Loss and Process Analysis

In this paper a new model GEOQ is proposed to decide the optimal lot sizing in production. The GEOQ modifies the classical EOQ method in several aspects. First it considers that there is always a probability that the production goes out-of-control; then it takes the time the process goes out-of-control as a stochastic quantity; and finally it adds quality loss to the economic models. The quality loss is calculated according to Taguchi’s quadratic loss function. and depends on the process failure models. Therefore, the optimal lot sizing is decided not only by the set-up cost and the holding cost but also by the quality loss during the manufacturing process.