An application of reliability centered maintenance using RPN mean and range on conventional lathe machine

Abstract

RCM provides a structured and practical approach for arriving at an acceptable maintenance strategy for each component of a given system. In this paper, a study on reliability centered maintenance (RCM) has been conducted to reduce the total number of failures and its effects on the conventional lathe machine. The risk priority number (RPN) is, one of the key factors in determining the critical ranking of a failure mode of the mechanical equipment but there is a drawback in determining the critical ranking from RPN. There might be more than one failure modes which can share the same RPN number and therefore critical ranking cannot be assigned to those failure modes. Initially, the Severity, Occurrence and Detection rating integrating with failure mode and effect analysis (FMEA) is taken from several experts and then RPN is calculated for each of those experts. Then the criticality of the failure mode of the functionally significant items of conventional lathe machine is judged on the basis of mean RPN value as well as using the range. Overall the risk or criticality level of each failure mode is identified. After that, RCM logic is used for selection of a proper maintenance strategy for each failure mode.