Machine breakdown recovery in production scheduling with simple temporal constraints

Abstract

One of the problems of real-life production scheduling is dynamics of manufacturing environments with new production demands coming and breaking machines during the schedule execution. Simple rescheduling from scratch in response to unexpected events may require excessive computation time. Moreover, the recovered schedule may deviate prohibitively from the ongoing schedule. This paper studies two methods how to modify a schedule in response to a machine breakdown: rightshift of affected activities and simple temporal network recovery. The importance is put on the speed of the rescheduling procedures as well as on the minimum deviation from the original schedule. In addition, this paper models the problem as a Mixed Integer Program and compares the proposed algorithms to the model using the mosek optimizer. The scheduling model is motivated by the FlowOpt project, which is based on Temporal Networks with Alternatives and supports simple temporal constraints between the activities.