A scheduling problem, solution approaches and applications for energy saving in flexible job shops

Energy is one of the production requirements which becomes more important day by day since resources are limited. Therefore, this study focuses on energy saving with scheduling solutions for flexible job shops. For this purpose, a novel mixed integer linear programming model which has a quaternary cost function, was built for flexible job shops. The capability of the model was tested with actual manufacturing data which was collected from a textile finishing plant. Metaheuristic methods have researched for large scale scheduling problems. Different sized problems have been solved successfully with the improved iterated local search algorithm. In the proposed model, sequence dependent set-up times, sequence dependent set-up energy usages and time-of-use energy tariff are tackled as a whole and energy saving can be achieved.