Comparison of inspection policies

In this paper, the authors compare an optimal inspection policy by Barlow et al. with nearly optimal ones by Kaio and Osaki, Munford and Shahani, and Nakagawa and Yasui. They obtain the result that, for the Weibull and gamma distributions, there are no significant differences between the optimal and nearly optimal inspection policies. The authors recommend the simpler-to-compute policy of Kaio and Osaki since it is nearly optimal.