A note on active redundancy allocations in kk-out-of-nn systems

Consider a kk-out-of-nn system comprising the components C1,…,CnC1,…,Cn. Suppose that two spares, R1R1 and R2R2, are available for active redundancy in one of the following two ways: R1R1 with C1C1 and R2R2 with C2C2, or R1R1 with C2C2 and R2R2 with C1C1. Following Romera et al. (2004) and Valdés et al. (2010), we compare lifetimes of the resulting systems with respect to the criterion of stochastic precedence.