Producibility index with process capability and manufacturing cost

A product design which does not include downstream requirements often leads to additional redesign due to unexpected high manufacturing cost or post-production service and support. This paper presents a producibility index vector which incorporates both quality and cost requirements of product design. Quality characteristics are classified into three categories (critical, major, and minor) according to their relative importance. Four process capability indices(PCIs) are calculated; three for each category and one for the overall performance of the characteristics in these categories. Design with high PCIs can cause significant manufacturing cost. Therefore, we include the manufacturing cost as the fifth element of the index vector. Using this five-element producibility index vector, we can compare competing product/process designs, and select one which is best in view of the index vector. This measure can help to integrate initial design ideas and actual production concerns, and to shorten the time to market of new products.