چارچوب مدیریت نقص مبتنی بر فعالیت برای توسعه محصول An activity-based defect management framework for product development

1 Introduction In today’s environment, intense competition forces manufacturing firms to develop new products at an increasingly rapid pace to gain premium pricing and higher sales volume. This phenomenon is especially seen in hardware products. In quality engineering fields, tangible products with specific shape and separability are called hardware products (also called products), which are the most widely used in the industry and life field. Typical examples of tangible products include electronic equipment, automotive, medical devices, and DVD recorders, etc. Faster market development leads to higher design defect risk in products. Given the continuously growing possibilities provided by technologies and their wider range of applications, products are becoming more and more complicated to meet customer’s various demands, thus increasing the risks of product design defect. An adequate defect risk management is indispensable to avoid or reduces cost and time for rework of design activities as well as to achieve an delivered quality level. Accidents caused by product design defects can lead to devastating consequences. For example, failure of communication signals led to the Wenzhou Train high speed crash disaster in China on July 23, 2011, in which 40 people were killed and at least 192 were injured. The failure of equipment in this disaster was caused directly by the design defect of the electrical control system. Design defects determine whether a company will survive or fail. Enterprises suffer from enormous economic losses as well as reputation crisis because of design defects. Managing product defect throughout the development process is thus becoming crucially important, as it is a means to improve a product’s reliability and security. The management of design defect consists of defect identification, defect removal, and defect control and so on. Product design defect identification is especially crucial and indispensable for design defect management. Moll pointed that defects should be identified and removed as early as possible. Otherwise, defects may be propagated and dispersed to the subsequent phases of product development. (Moll et al., 2004). A case of 68 projects is given in Ebert’s study, where early defect detection activities decreased the residual defects to 70%. (Ebert et al., 2001). Jacobs et al. also found that an increased likelihood of injection as well as propagation of defect results to higher amounts of defect in the final product (Jacobs et al., 2005). All kinds of industrial product regulations which focus on the identification of product defects have been established by a nation. But there are still many problems such as backward regulations, insufficient attention to the design defects which exist in the product quality management system. Some research pays more attention to design defects of the specific product. Li pointed out that violent wind, drastic turbulence, and sudden change of wind direction are major factors of wind turbine failures by collecting historical data of wind turbine failures (Li et al., 2013). Fan proposed basic theory system for fault tolerance and fault rectification design of electro mechanical products (Fan et al., 2007).