Reliability Prediction of Remanufactured Product: A Welding Repair Process Case Study

Many experts agree that effective management of system reliability and reliability validation during product development is a key to achieve superior time to market and life cycle quality. However, reliability performance prediction is a common problem faced by all product developers and it is usually a difficult task. A related problem is to determine the reliability performance of a remanufactured product. Clearly, the remanufacturer would like to know the expected reliability of their product before entering it into service, but unlike an original manufacturer, they will typically have much less information available to them. In this paper, a general framework for reliability prediction in a remanufacturing environment is proposed. A case study of a remanufactured engine cylinder head that has had a fatigue crack repaired by a welding process will be presented in order to illustrate the process. The approach combines the use of Failure Modes and Effects Analysis (FMEA), Experimental Model Building, Monte Carlo Simulation and Linear Elastic Fracture Mechanics (LEFM) to generate a reliability estimate. The FMEA and physical modeling will be used to generate a model that relates the welding process control parameters to the fatigue performance of the test specimens. Monte Carlo Simulation techniques and LEFM will build on the above model to relate the process control parameters to the reliability performance. The paper concludes by discussing the utility of such a model and approach, and presents the future research agenda.Copyright © 2006 by ASME