| The purpose of this research is to present a practical mathematical model to estimate the cost of tolerances, and the implementation of an approach to incorporate part tolerances and quantify the cost of tolerances for individual parts as well as multiple components in a product. Quantitative and qualitative factors that contribute to dimensional variation in manufacturing have been identified and briefly described. Quantitative factors with a major influence in the cost of tolerances have been incorporated into the mathematical model.;The integrated approach consists of a modular computerized system to support cost estimates for product designs. The areas addressed in this approach include: product design requirements, product cost estimation using activity based costing, manufacturing and assembly resources consumption and availability, and tolerances and their role during the concurrent design of products and processes.;The mathematical model has been illustrated with an example for turning operations solved using the SAS$spcircler$ system. The integrated approach, implemented using a relational database system, was applied in a company in the process of developing a new control drive mechanism for nuclear reactors. Stainless steel nuclear grade components for boiling water reactors are manufactured utilizing complex processes and many different machining techniques. The production of these products require very tight tolerances, very high quality, and a great deal of documentation due to government regulations. Two new products for the control drive mechanism were chosen for this study to define a real situation. Reports on the cost of tolerances for individual or multiple components can be obtained through the manufacturing module in the integrated approach. |
