EARLY SIMULTANEOUS INFLUENCE OF MANUFACTURING ACROSS STAGES OF THE PRODUCT DEVELOPMENT PROCESS: IMPACT ON TIME AND COST

This paper focuses on the concept of ESI (early simultaneous influence) as a cornerstone of concurrent engineering. How much influence downstream functions such as manufacturing engineering should exert in product design decisions is investigated by stage of development. Six stages were defined as: (1) research, (2) product concept, (3) prototype and test, (4) final design, (5) tooling and facilities, and (6) ramp-up to full production. Performance is measured as time compression at the tooling and facilities stage and reduction in manufactured cost. Results from analysis of 74 companies suggest that manufacturing influence has significant effects on performance at the first three stages. Its peak impact is at the third stage, a crossroads of work by up and downstream functions. If the design is new, however, the peak impact of ESI is earlier as indicated by significant interaction effects at the research and product concept stages. We also show that high levels of manufacturing influence at the end stage have a weak negative interaction effect with performance when designs are new. To the extent that high levels of manufacturing influence within their own domain preclude reciprocal influence by upstream functions, this result is consistent with the notion of concurrency as simultaneous influence by multiple functions at all points along the value chain.