Reliability Allocation Method for Remanufactured Machine Tools Based on Fuzzy Evaluation Importance and Failure Influence

Reliability is the key performance indicator for remanufactured machine tools to be approved by customers. Reliability allocation is an important task that needs to be done in the design phase of remanufactured machine tools to ensure that remanufactured products meet the reliability target requirements. A reliability allocation method for remanufactured machine tools is proposed based on fuzzy evaluation importance and failure influence of each component. The importance of each component is evaluated by five indicators such as complexity of structure, maturity of technology, criticality of fault, difficulty of maintenance, and severity of service condition, in which their weights are determined by the method of analytic hierarchy process (AHP). Failure influence is determined by the proportion of downtime caused by each component in total downtime of machine tools. Finally, the proposed method is illustrated in a numerical case study of NC lathe remanufacturing.