Optimum Process Mean Setting for Product with Rework Process

The determination of the optimum process mean has been a major topic in statistical process control. It directly affects the process defective rate, production cost, scrap cost, and rework cost. In 2000, Lee et al. presented a filling problem for determining the optimum process mean and screening limits. They considered three grades of product, assumed a normal quality characteristic, and adopted the piecewise linear profit function for measuring the profit per item. However, they have not included the scrap cost and the perfect rework process in their model. In this paper, we further propose a modified Lee et al.' s model with rework process for determining the optimum process mean. Both perfect rework and imperfect rework processes for the product are considered in the model.