Bivariate optimal replacement policies for multistate degenerative systems

This paper studies the maintenance problem of a multistate degenerative system with k‐working states and l‐failure states. The long‐run average cost for a multistate degenerative system under different bivariate replacement policies is derived. Existence of optimality under the aforesaid bivariate replacement polices are deduced. Numerical examples are given to illustrate the results developed in this paper.