Research on the decomposition approach to product reliability for manufacturing process

Currently, the theoretical research of reliability is mainly focused on product design, on the other hand, we do not have a sufficient knowledge on the reliability assurance for manufacturing process. Lots of engineering cases show that the product reliability usually experiences significant degradation during the phase of manufacturing, which reveals the research weakness on manufacturing reliability. Recently, the major problem for industry is that how to keep the reliability of products manufactured in the mass production phase as high as that achieved in the design phase and develop the related standard which can be followed directly by the reliability engineer. To deal with this problem, a decomposition model of product reliability for manufacturing process is presented. In this model, the design requirements of product reliability are transferred to the manufacturing process improvement methods by the structure of product, manufacturing features and failure causes. According to the model, we propose a reliability decomposition approach based on the waterfall decomposition of the House of Quality (HoQ) in Quality Function Deployment (QFD), the product reliability indexes are transferred to process parameters by matrix multiplication. And then, we find the most valuable process improvement methods through multi-layer fuzzy comprehensive evaluation optimization methods which will enhance the product reliability effectively. The method is then verified with an example of a shell component of a missile, the result shows that the decomposition approach is a useful tool to keep the reliability of products in mass production phase.