On Optimal Operational Sequence of Components in a Warm Standby System

We consider an open problem of optimal operational sequence for the $1$-out-of-$n$ system with warm standby. Using the virtual age concept and the cumulative exposure model, we show that the components should be activated in accordance with the increasing sequence of their lifetimes. Lifetimes of the components and the system are compared with respect to the stochastic precedence order. Only specific cases of this optimal problem were considered in the literature previously.