Replacement Overtime and Middle Policies

Originally, replacement last was discussed to replace an operating unit without stopping successive working cycles by Zhao and Nakagawa (Eur J Oper Res 223:141–149, 2012, [7]); however, the approach of replacing over a planned measure, i.e., delaying replacement actions over the planned time T until the running works have been completed by Nakagawa (Advanced reliability models and maintenance policies. Springer, London, 2008, [30]), was provided as another choice to make replacement easier.