Study Of Work-Rest Scheduling To Consider Human Factor’s Quality In Furniture Assembly Shop

This thesis is to research the factors which affect quality of products in the furniturecomponents’assembly process, according to the theory of ergonomics and systemengineering. Interpretive structural model of factors affecting main qualitydefect—bruise and scratch is built, from six aspects man, machine, material, method,measurement and environment, combination with statistical data of quality defectsand ISM specialists. The major cause is workers’fatigue; others are poor illumination,staff skill and salary mechanism, etc. Based on the current research of physical workcapability, workload mechanism and energy expenditure, combining with actualproduct situation, furniture assembly shop operators’workload are divided into threegrades. In order to improve the productivity and reduce the effect of workers’fatigue,the single worker work-rest schedule model is constructed, where two objectivesinclude minimizing the work time of completing all jobs and minimizing worker’sextra energy expended by worker due to work longer than the maximum acceptablework duration. A reasonable work-rest schedule can renew workers’strength, so makehuman error reduced, and then lower quality defects. A GA-based algorithm is used toresolve multi-objective optimization problems. So we can obtain the schedule, whichcontains task schedule, the duration of rest, the number of rest and the place of rest.Finally, case study shows that our proposed model is effective in scheduling work andrest for a single worker. In addition, for more than one satisfactory solution can beusually obtained, decision makers can choose the one that is more effective accordingto actual conditions.