Reliability function deployment in conceptual product development phases.

摘要

Most of the design for reliability research is based on probability oriented analysis techniques. These techniques are used to analyze test data to evaluate product performance subsequent to the design stage of the product development process. This dissertation represents a new framework, Reliability Function Deployment (RFD) with the aim of focusing on customer-related reliability characteristics early enough in the product development life cycle to improve the reliability of a system beyond the traditional methods of increasing component reliability. This new framework consists of step-by-step activities for integrating reliability into the conceptual design phases. Activities covered in this research utilize new scientific methods and techniques, the core theory of design for six sigma, i.e. quality function deployment, mechanism of failure, TOPSIS selection matrix, model building techniques, Monte Carlo simulation, stress strength interference and many others, to estimate product reliability early at the concept phase. The research details an application of RFD framework to a simple example, a Cantilever Beam design concepts selection, and also to a more complex problem, a Pole Clamp fracture issue pilot project. Reliability of the design concepts are calculated and added to the selection criteria to enhance concepts selection and ultimately qualify the best concept among many. Results of the proposed RFD framework clearly illustrate how wrong concepts can be easily chosen without the rigor of the proposed RFD approach. In conjunction with the RFD framework, this research have introduced a new approach to prioritize FMEA Risks using Rough Set Theory to manage and prioritize FMEA risk levels.