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

Year 2019, , 123 - 136, 15.08.2019

Hazel Durmaz , Melik Koyuncu

https://doi.org/10.35860/iarej.501847

Cited By: 2

Abstract

In order to serve the purpose of the study, two different mathematical models which belong to production line to were developed to assign workforces to the jobs who have different skills. The assignment model had been examined on a product that produced in a specified welding line in the automotive industry. All labor levels related to the product were analyzed by time study firstly and then the collected data were analyzed. New skill levels of workers, skill matrix were determined according to skill requirements (min. and max.) of the jobs. All collected data which come from time studies and skill matrix were used as an input parameter in the mathematical model that aim to minimize the unit production cost. Reports of mathematical models showed that it is necessary to assign right skilled worker to the job to minimize the production cost and increase the efficiency online. In this case the implementation was made by selecting a product in the welding manufacturing line. In the line, there are 5 stations that have 14 jobs and 27 operators. A modeling has been carried out in which the operators can be assigned to jobs under optimum conditions, based on assignment criterias. Models of sensitivity analyzes and statistic report results obtained 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 and by assigning right conditions to the model.

Keywords

Mathematical modelling, assignment problems, time study

References

• 1. Hillier, F.S., Lieberman,G.J., Introduction to Operations Research, 2010, New York:McGraw-Hill,Inc.
• 2. Nash,J., The Dantzig simplex method for linear programming. Computing in Science & Engineering, 2000. p.29-31.
• 3. Hitchcock, F., The Distribution of a Product from Several Sources to Numerous Localities. Studies in Applied Mathematics, 1941. p.224-230.
• 4. Kuhn, H. W., The Hungarian Method for the Assignment Problem.Naval Research Logistics Quarterly, 1955. (2): p.1-2.
• 5. Koopmans,C., and Beckmann,M., Assignment Problems and the Location of Economic Activities, Econometrica, 1957. 25(1): p. 53-76.
• 6. Ferjani,A.,Ammar,A.,Pierreval,H.,Elkosantini,S., A simulation-optimization based heuristic for the online assignment of multi-skilled workers subjected to fatigue in manufacturing systems, Computers & Industrial Engineering, 2017. p. 663–674.
• 7. Brilon,S., Job Assignment with Multivariate Skills, Preprints of the Max Planck Institute for Research on Collective Goods, 2010.
• 8. Moreira,M., and Costa,A., A minimalist yet efficient tabu search algorithm for balancing assembly lines with disabled workers, XLI SBPO Pesquisa Operacional na Gestão do Conhecimento, 2009: p. 660-671.
• 9. Li,Q., Gong ,J., Tang ,J.,Song,J., Simulation of The Model of Workers Assignment in Cellular Manufacturing based on the Multifunctional Workers, Chinese Control and Decision Conference, 2008.
• 10. Ammar, A., Pierreval, H., Elkosentini, S., Worker Assignment Problems in Manufacturing Systems: a Literature Analysis, Rabat-Morocco IESM Conference, 2013.
• 11. Nizami,S.,Khan,F.,Khan,N.,Inayatullah,S.,Inayatullah,S., A New Method for Finding the Cost of Assignment Problem Using Genetic Algorithm of Artificial Intelligence, International Journal of Latest Trends in Computing, 2011. 2(1): p.135.
• 12. Kotwal,J.,and Dhope,T., Solving Task Allocation to the Worker Using Genetic Algorithm, International Journal of Computer Science and Information Technologies, 2015. 6 (4): p.3736-3741.
• 13. Cesanı, V., and Steudel, H., A study of labor assignment flexibility in cellular manufacturing systems, Computers & Industrial Engineering, 2005. 48: p.571-591.
• 14. Heimerl,C., Kolisch, R., Work assignment to and qualification of multiskilledhuman resources under knowledge depreciation and company skill level targets, International Journal of Production Research, 2010. 48(13): p.3759-3781.
• 15. Norman, B., Tharmmaphornphilas, V., Needy, K., Bidanda, B., and Warner,R., Worker assignment in cellular manufacturing considering technical and human skills, International Journal of Production Research, 2002. 40(6): p. 1479-1492.