Ergonomic Evaluation and Improvement Measures for Shiftwork Systems of Large Scale Manufacturing Enterprises in Korea

Objective: The aims of this study are to survey shiftwork systems performed in large scale manufacturing enterprises of Korea, to evaluate the shift systems from the ergonomics viewpoint, and to propose some measures for improving the shift systems. Background: Existing studies on the shiftwork systems have focused on health effects such as cardiovascular diseases, gastrointestinal disorders, metabolic syndrome, psychological well-being, sleep, etc., and occupational accidents. Although the shift systems should be ergonomically designed in order to reduce effects on health, circadian rhythm, sleep, accidents, etc., there has been no research on ergonomic evaluation for the shift systems performed in Korea. Method: The shiftwork systems were surveyed for ten large manufacturing companies (three electronics, three automotive, two chemical and two steel companies) through personal communication, literature survey, search through portal web sites and Apps. Ergonomic evaluations for the ten companies' shift systems were conducted by 16 ergonomic recommendations proposed by Knauth (1997), Knauth and Hornberger (2003). Results: The results showed that the shift system of 3 team 3 shift without periodic duty-off days was still adopted in an electronics manufacturing company. The shift cycles for most companies surveyed were longer than four days, which resulted in slow rotation with four or more days' consecutive duty-on days. Four-out-of-ten companies investigated did not adopt the forward rotation ergonomically recommended, but the direction of rotation such as morning-night-evening. In addition, except for three automotive companies, seven companies violated ergonomic recommendations of avoiding work on weekends or having some free weekends with at least two consecutive days off. Based on these results, two alternatives with periodic days off on weekend and forward rotation were proposed. Conclusion: The shift systems for the ten companies have several problems in light of existing ergonomics recommendations. Application: The results of this study might help to improve the current shift systems performed in companies of Korea.

우리나라 대기업 제조업 교대근무제의 인간공학적 평가 및 개선 방안