MODELING MANUFACTURING QUALITY CONSTRAINTS FOR PRODUCT DEVELOPMENT

When bringing a new or improved product to market, a design and manufa cturing enterprise can speed the process and improve the result by und erstanding and designing within the manufacturing process used. We pro pose process characterization modeling and experiments aimed at uncove ring their effect upon product functional requirement metrics. In a re al industrial design and manufacturing enterprise, however, social and managerial problems drive any such design-for-manufacturing integrati on modeling. Modeling and experiments are limited to activities that p rovide direct answers to short-term real identified problems. This mea ns that only a continuous improvement approach is practical to constru ct process constraint models. We develop and demonstrate a methodology to quantify the quality constraints imposed on a product design by it s manufacturing process. We start with the sequence of operations tran sforming the incoming material into the final product, which is diagra mmed into a topology of the operational sequence. Next, performance me trics are identified which correspond to the customer requirements. Us ing engineering analysis, a basic model is developed relating known pr oduct and material variables to the metric. Production data, either fr om designed experiments or from natural variation occurring during pro duction, are measured to validate the basic model. Next, each operatio n in the process topology is analyzed for potential effect upon the mo del. Modes of impact of each operation upon the metric are conceived, and quantified into the basic model. These modes become either support ed or not by the production data. The methodology, therefore, is one o f continuously improving the understanding of the process imposed cons traints to improve the product. We demonstrate the methodology with a running example, characterizing the process imposed constraints upon a low temperature cc-fired ceramic circuit assembly.