Concurrent optimization of process tolerances and manufacturing loss

This paper proposes a non-linear programming model to design process tolerances by minimizing the manufacturing loss due to non-conforming production. The model incorporates with the process capability of equipment to standardize the process tolerances, and utilizes the cumulative standard normal probability function to explore the scrap rate of operations with respect to the tolerances allocated. Therefore, the process tolerances can be economically designed to be producible. Results of comparison with other methods indicate that robust process tolerances can be generated by the proposed model.