Studying of loom loading problems with optimum lot sizes and an application in weaving workshop

In a highly competitive production environment, companies have to reduce their operations costs, increase their qualities and increase their productivity in order to survive. Production planners have to make the decisions properly and optimally when scheduling the tasks/jobs to the machines. The decision of which processes or work centers will do the tasks/jobs refers to production scheduling. They often look for a way to minimize operational and setup costs, due date delays, inventory costs or job completion time when scheduling. In this study, n jobs are assigned to m parallel identical machines in a sequence according to the objective function. The weighted objective function has been determined to minimize the total completion time (makespan) and total no of tardy jobs. For this aim, sequence dependent setup times, processing times of jobs and initial occupancy of the machines are used as a constraints. The study was carried out in the weaving facility of a fully integrated textile factory and the data used for the solution were taken from real life problem. A mathematical model was developed for the solution of the application and additionally heuristic methods were evaluated for the solution of real life problems and the scheduling problem was solved using the Simulated Annealing algorithm. The solution of the mathematical model and the solution of the Annealing Simulation algorithm are compared.