Customization has b een identified as a competitive strategy by an increasing number of companies. High degree of customization also requires higher quality. The number of custom ized products is few, even single. Com plex customized products also have high dim ensional critical quali ty characteristics and com plex relationship among influence factors, and it is difficu lt to identif y the source of variation . Consequently, trad itional qua lity co ntrol m ethos would no t be eas ily adapted to customizat...