Robust scheduling on a single machine using time buffers

This article studies the scheduling of buffer times in a single-machine environment. A buffer time is a machine idle time in between two consecutive jobs and is a common tool to protect a schedule against disruptions such as machine failures. This article introduces new classes of robust machine scheduling problems. For an arbitrary non-preemptive scheduling problem 1|β|γ, three corresponding robustness problems are obtained: (i) maximize overall (weighted) buffer time while ensuring a given schedule's performance (with regard to the objective function γ); (ii) optimize the schedule's performance (with regard to γ) while ensuring a given minimum overall (weighted) buffer time; and (iii) find the trade-off curve regarding both objectives. The relationships between the different classes of problems and the corresponding underlying problems are outlined. Furthermore, the robust counterparts of three very basic single-machine scheduling problems are analyzed.