APPLICATION OF REBA AND KARAKURI KAIZEN TECHNIQUES TO REDUCE ERGONOMIC RISK LEVELS IN A WORKPLACE

Repetitive works and the works done with inappropriate body postures cause musculoskeletal disorders and workforce losses. Design, technology, and humans must come together in ergonomic conditions. In this study, the ergonomic risk levels that employees in automotive production lines being exposed to were determined by the rapid entire body assessment (REBA) method and by considering anthropometric measurements and ergonomic body postures at a line with high risk level, and a shelf system was designed in accordance with the Karakuri working principle. Through the computer-aided design, the system operation was simulated and solutions for ergonomic risks could be provided before the production. The ergonomic risk level, which was “high” in the current situation, could be reduced with the newly designed mechanism, and an ergonomic workspace could be provided for employees. In the new situation, the ergonomic risk level is “low.” In addition to ergonomic improvements, as the manual transportation works of the employee were eliminated, the cycle time of the line, which was 120 s in the first state, was reduced to 100 s after the use of the Karakuri mechanism and the efficiency of the line increases by 17%.