Determination of the optimum target value for a production process with multiple products

This paper considers the problem of determining the optimum target value of the process meant for a production process where multiple products are processed. Every outgoing item is inspected, and each item failing to meet the specification limits is scrapped. The quality characteristics of the products are assumed to be normally distributed with known variances and a common process mean. A profit model is constructed which involves selling prices, costs of production and inspection, and losses due to the scraps. The common process mean is determined so that the expected profit is maximized. A method of finding the optimum common process mean is presented and an example from electronic device (4L PBGA) production process is given.