INTRODUCTION OF THE PROPER MODEL, AN OPTIMIZATION METHODOLOGY TO REDUCE COST AND LEAD-TIME FOR EXISTING DESIGNS OF MACHINED GOODS

摘要

Manufacturers in the USA are facing increasing pressure to offer products capable of competing with low-cost-country vendors, forcing them to continuously lower prices and shorten delivery times. Simultaneously, shop employees are discovering inefficiencies in released designs after they have already gone into production, leading to an inflated manufacturing cost, affecting the manufacturers' margins in every sale. This paper explores a viable solution to this problem by introducing the PROPER (Product Redesign, Optimization of Processes, and Effectiveness Review) Model, a new methodology created to simplify existing designs and lean-out the manufacturing processes. Unlike existing optimization methodologies, such as Lean or Six-sigma, which focus heavily on improving the manufacturing process only, the PROPER Model encompasses optimizations to any existing design, provides guidelines for multiple optimization approach to the manufacturing processes, and increases employees' ownership for quality verification with the goal of reducing cost and production lead-times. A practical application of this new model was implemented to Safety Relieve Valve components with the purpose of demonstrating that cost and lead-time reduction can be accomplished using the steps outlined by this methodology. The full implementation process is summarized and presented in this paper, including the outcome of cost reduction of up to 25% and an average lead-time decrease of 16%. The PROPER Model was initially developed to reduce cost and lead-time for Primary Pressure-Retaining Components in Safety Relief Valves, but it could be applied in other existing products and industries as a mean to identify and reduce waste on existing component designs.