Mathematical Models for Corrective Maintenance of Aging Multi-state Systems
by
Ilia Frenkel
Center for Reliability and Risk Management, Sami Shamoon College of Engineering, Beer Sheva, 84100, Israel
Coauthors: Anatoly Lisnianski (The Israel Electric Corporation Ltd., Israel) Lev Khvatskin (Sami Shamoon College of Engineering, Israel)

This paper considers an aging Multi-state system used under variable demand conditions, where the system failure rate is known increasing function. The system can fall into unacceptable state in two reasons: either through performance degradation because of failures or through an increasing in demand. After any failure, corrective maintenance is performed by an external repair team. Repair rate and cost of repair are determined by a corresponding maintenance contract with a repair team. In order to choose the best maintenance contract, a total expected cost during specified time horizon should be evaluated for aging system. In this paper, a method, based on a piecewise constant approximation for failure rate increasing function via building the Markov Reward Model in order to assess lower and upper bounds of total expected cost is suggested.

Failure and repair rates define the transition matrix of corresponding Markov process. Income cost, operation cost, repair cost and penalty cost for system failures are taken into account by the corresponding reward matrix definition.

A numerical example is presented in order to illustrate the approach.

Date received: November 21, 2007

Copyright © 2007 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # caub-22.