Reliability evaluation of generalised multi-state k-out-of-n systems based on FMCI approach

Most studies on k-out-of-n systems are in the binary context. The k-out-of-n system has failed if and only if at least k components have failed. The generalised multi-state k-out-of-n: G and F system models are defined by Huang etal. [Huang, J., Zuo, M.J., and Wu, Y.H. (2000), 'Generalized Multi-state k-out-of-n: G Systems', IEEE Transactions on reliability, 49, 105-111] and Zuo and Tian [Zuo, M.J., and Tian, Z.G. (2006), 'Performance Evaluation of Generalized Multi-state k-out-of-n Systems', IEEE Transactions on Reliability, 55, 319-327], respectively. In this article, by using the finite Markov chain imbedding (FMCI) approach, we present a unified formula with the product of matrices for evaluating the system state distribution for generalised multi-state k-out-of-n: F systems which include the decreasing multi-state F system, the increasing multi-state F system and the non-monotonic multi-state F system. Our results can be extended to the generalised multi-state k-out-of-n: G system. Three numerical examples are presented to illustrate the results.