Pérez-ocón, Rafael et Gámiz-pérez, M. Luz, On the HNBUE property in a class of correlated cumulative shock models, Advances in applied probability , 27(4), 1995, pp. 1186-1188
Conditions for a correlated cumulative shock model under which the system failure time is HNBUE are given. It is shown that the proof of a theorem given by Sumita and Shanthikumar (1985) relative to this property is not correct and a correct proof of the theorem is given.