Track: Maintenance Services

Abstract

Determination of the best approach to preventive replacement maintenance on repairable engineering systems can guarantee maximum efficiency, reliability and sustainability. The availability approach can be considered more appropriate in system replacement analysis, short of reliability; since it includes both reliability and maintainability. The paper investigates the economic replacement period for a typical repairable system, in a maintenance intensive industry. The system had a design replacement period based on fixed age, which was compared with the replacement period decided on the results of maintenance cost analysis. The data used for the analysis was taken from four centrifugal pumping units of a manufacturing industry, called Rex Company in this paper for privacy. The mean availability of the system over the studied period was 49.9%. The result show that the 19 years replacement period obtained from analysis of maintenance cost data is in very fair agreement with the designers’ estimate of 20 years, though the Authors are not privy to the method of useful life estimation used by the designers. However, the authors argue that the research results is superior to the fixed age replacement period given by the manufacturers. This conclusion is predicated on the non-linearity of the availability of the centrifugal pumps during the study stretch. The result also shows that availability evaluation can offer a good insight to determining the replacement period of deteriorating systems.