Availability of a Parallel Redundant Complex System

This paper considers a complex system consisting of three subsystems (A, B, C) in series with a single repair facility. Subsystem A consists of N non s-identical units in series. Subsystem B has two s-identical units in parallel. Subsystem C consists of M non s-identical units in such a way that the failure of one unit causes the whole system to degrade, but not fail. Laplace transform and supplementary variable techniques are used to solve the model under several repair disciplines.