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Optimal replacement policies for multistate deteriorating systems
Author(s) -
Teresa Lam C.,
Yeh R. H.
Publication year - 1994
Publication title -
naval research logistics (nrl)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.665
H-Index - 68
eISSN - 1520-6750
pISSN - 0894-069X
DOI - 10.1002/1520-6750(199404)41:3<303::aid-nav3220410302>3.0.co;2-2
Subject(s) - monotonic function , weibull distribution , state (computer science) , mathematical optimization , average cost , state dependent , computer science , economics , mathematics , mathematical economics , microeconomics , statistics , algorithm , mathematical analysis
We consider state‐age‐dependent replacement policies for a multistate deteriorating system. We assume that operating cost rates and replacement costs are both functions of the underlying states. Replacement times and sojourn times in different states are all state‐dependent random variables. The optimization criterion is to minimize the expected long‐run cost rate. A policy‐improvement algorithm to derive the optimal policy is presented. We show that under reasonable assumptions, the optimal replacement policies have monotonic properties. In particular, when the failure‐rate functions are nonincreasing, or when all the replacement costs and the expected replacement times are independent of state, we show that the optimal policies are only state dependent. Examples are given to illustrate the structure of the optimal policies in the special case when the sojourntime distributions are Weibull. © 1994 John Wiley & Sons, Inc.