Reliability analysis of k-out-of-n: F balanced systems with multiple functional sectors.

• New conceptions of balance are introduced based on real backgrounds. • Balance differences of any two groups are considered for the first time. • The forced-down units are considered as warm-standby units for the first time. • New models for balanced systems with multiple functional sectors are built. • Two case studies are presented to validate the applicability of the new models. In this paper, new concepts of balanced systems are proposed based on real engineering problems. The system under study consists of l groups and each group has n functional sectors. The conception of balance difference is proposed for the first time. It is assumed that unbalanced systems are rebalanced by either forcing down some working units into standby or resuming some standby units into operation. In addition, a case that the forced-down units are subject to failure during standby is studied in this paper. Based on different balanced cases and system failure criteria, two reliability models for balanced systems are developed. The proposed systems have widespread applications in aerospace and military industries, such as wing systems of airplane and unmanned aerial vehicles with balanced engine systems. Markov process imbedding method is used to analyze the number of working units in each sector for each model. Finite Markov chain imbedding approach and universal generating function technique are used to obtain the system reliability for different models. Several case studies are finally presented to demonstrate the new models. [ABSTRACT FROM AUTHOR]