Reliability analysis of a two-unit general parallel system with (n-2)(n-2) warm standbys

A parallel (2,n-2)(2,n-2)-system is investigated here where two units start their operation simultaneously and any one of them is replaced instantaneously upon its failure by one of the (n-2)(n-2) warm standbys. We assume availability of n   non-identical, non-repairable units. The unit-lifetimes in full operational mode and in partial operational mode have general distribution functions GiGi and Hi(i=1,…,n) respectively. The system reliability is evaluated by recursive relations.