A methodology for comparing age-based maintenance and condition-based maintenance using economic measures of performance

Scope and method of study. The purpose of this research is to examine the relationship between the cost of asset failure, the cost of performing condition-based maintenance, the cost of performing age-based maintenance, and the discriminatory ability of the condition-based maintenance measurement process, with regard to selecting the economically preferred maintenance strategy. To accomplish the comparison between age-based maintenance and condition-based maintenance, the research introduces a degradation function to describe the condition of an asset. The scope of this research is limited to assets that have a Weibull distributed density function. The general approach of the research is to calculate the total cost for corrective maintenance, age-based maintenance, and condition-based maintenance under different levels of failure, maintenance, and discriminatory values. The economically preferred strategy is that strategy with the lowest total cost.; Findings and conclusions. Corrective maintenance is preferred over age-based maintenance and condition-based maintenance when the Weibull shape parameter is equal to one or when the cost of failure is equal to the cost of performing age-based maintenance or condition-based maintenance. Graphical aides are presented to help a practitioner better understand how changes in the value of the cost of failure, the cost of performing condition-based maintenance and the implementation and continuation cost of condition-based maintenance can change the economically preferred maintenance strategy selection. A maintenance strategy selection decision model is presented to predict the economically preferred maintenance strategy given the Weibull shape parameter value, standardized costs of asset failure, and the standardized cost of performing condition-based maintenance.