“…A relevant problem in reliability theory is to determine the optimal replacement policy (under different criteria) for the components in a given system structure. Many results have been obtained under the assumption of independent components (see, eg, Barlow & Proschan, 1975;Belzunce, Martínez-Riquelme, & Ruiz, 2018;Boland & El-Neweihi, 1995;Chahkandi et al, 2016;Boland, El-Neweihi, & Proschan, 1992;Li & Ding, 2010;Natvig, 2011;Shaked & Shanthikumar, 1992). Different assumptions have been made for the redundant components.…”