Heuristic Reactive Rescheduling Algorithms in the Advanced Scheduling Add-on for ERP

In the paper there are described some rescheduling algorithms which are implemented in the advanced planning and scheduling system, namely PEN System, which is an add-on for the Enterprise Resource Planning system and intended to be used to mitigate the impacts of potential exceptions disrupting shop floor level schedules. The rather simple and quick heuristic algorithms, namely Affected Operations Rescheduling and Active Wilkerson-Irwin algorithm are chosen to cope with the machine disruption. The algorithms are modified for more complicated and realistic enterprise environment model than the Job Shop or the Flexible Job Shop, namely for complex operations' precedence constraints described by any simple directed acyclic graph.