On Lifetime Optimization of Boolean Parallel Systems with Erlang Repair Distributions

We assume a Boolean parallel system with exponentially distributed component failure times. In order to maximize the lifetime of the system we consider a repairman with Erlang-k distributed repair time. By extending the classical exponential case k = 1 to k ≥ 2 different repair semantics arise in this context. In the case of restart repair semantics we show that a repairman should have few Erlang phases in order to maximize mean time to failure (MTTF). In the case k ≥ with full memory semantics an optimal repairman policy shows counter-intuitive repair behaviour dependent on the mean repair time.