Simulation of a non-stationary gamma wear process

Abstract

All mechanical components suffer from monotonically increasing wear/deterioration. A non-stationary gamma wear process can model such a wear by taking care of the temporal variability in the wear phenomenon; however, this makes the shape parameter of the gamma process a function of time leading to a problem in its simulation, especially so in the presence of other competing failure modes. This paper presents a method by which one can map a non-stationary gamma wear process to a mixed exponential process and demonstrate its suitability for analysis through a simulation package involving use of stochastic petrinets. A stochastic petrinet simulation package 'Timenet' compares the result of the above method with the analytically determined result through a Matlab program. The originality of the paper lies in demonstration of a method for analysis of a non-stationary gamma wear process through a simulation package.