Including the value of time in design for manufacturing decision making

Design for manufacturing (DFM) has been promoted as a way to enhance product development and production system performance. Current DFM practices encourage the minimization of the number of parts in a design through the physical integration of several geometric features in the same part. While this part integration often reduces the manufacturing cost of the product, it also can extend product development lead time, because complex parts typically require tooling with large lead times. This paper presents an economic model that makes explicit the trade-off between lower unit costs and longer product development time. This model is applied to a particular example in a field study of the application of DFM to Polaroid cameras.