R. SirovetnukulP. ChutimaMahidol UniversityChulalongkorn University2018-09-132018-09-132009-12-01IEEM 2009 - IEEE International Conference on Industrial Engineering and Engineering Management. (2009), 105-1092-s2.0-77949536104https://repository.li.mahidol.ac.th/handle/20.500.14594/27350The multi-objective worker allocation problems of single and mixed-model assembly lines having manually operated machines in several fixed U-shaped layouts are developed. Three objective functions are simultaneously minimized, i.e. number of workers, deviation of operation times of workers, and walking time. NSGA-II, an evolutionary optimization algorithm, searches only good solutions from the population, but a selection method should also discard the below-average solutions in order to avoid producing bad solutions. The COINcidence algorithm makes use of both good and not-good solutions with reward and punishment schemes to update a better generator. After getting the first objective of minimum number of workers, the rest are compared between NSGA-II and COIN in four measures for all testing problems. Each of the computational results gives a worker good task assignment and walking path. COIN is preferable to NSGA-II in most cases. ©2009 IEEE.Mahidol UniversityBusiness, Management and AccountingDecision SciencesEngineeringConference PaperSCOPUS10.1109/IEEM.2009.5373414