“…In this section, we study the interrelationships between the BFR family of [23], the IDMRL family of [24], the NWBUE family of [47], and the IDMTTF family of [27]. In the context of the abovementioned non-monotonic ageing classes, see the recent works [13,14,15,26,30,31,34]. Exploiting 'total time on test' (TTT) transform characterizations, [47] established that the NWBUE family of life distributions contains both IDMRL and BFR classes.…”