On discrete fix up limit time models for two formations

Due to insufficient resources or fix up personal, sometimes a failed system cannot be fix up completely at the precise optimal projected fix up limit time. Now, this paper is providing a chance of completing fixing up a failed system within a projected discrete fix up limit time \(PT (P=1, 2, 3, \dots )\) $PT(P=1,2,3,\cdots )$ for a fixed T, so as to provide a chance of completing a fix up action within a discrete time, which can reduce the unplanned downtime. A discrete fix up limit time function is constructed for series and parallel formations based on some assumptions. An example is provided to present the properties of the constructed fix up cost function.