Optimization of assignment problems in production lines with different skilled labor levels

In this study we developed a mathematical model to assign workforces to the jobs who have different skills in a production line. The assignment model had been examined on a product that produced in a specified welding line in the Automotive Industry. First, all labor levels related to the product were analyzed by time study and the collected data were analyzed. In addition to time study analyzes, skill levels of workers, skill matrix and skill requirements (minimum and maximum) of the jobs were determined. The collected data were used as an input parameter in the mathematical model that minimizes the unit production cost. The experiments showed that it is necessary to assign right skilled worker to the job to minimize the production cost and increase the efficiency. The implementation was made in the automotive sector by selecting a product in the welding manufacturing line. In the line, 5 stations have 14 jobs. There are 27 operators that can work together with this line in company. A modeling has been carried out in which the operators can be assigned to jobs under optimum conditions, based on assignment criterias. The statistic results obtained in the mathematical model reports and the model analyzes made on the model show the importance of the differences in the level of competence and the effect on the duration of the job as well as the decrease in the labor costs by assigning the correct workforce to the right job. Keywords: Mathematical modelling, Assignment Problems,Time Study