Ergonomic analysis and improvement for ease of work of post engine testing activities by using RULA and REBA techniques

The productivity and efficiency of any manufacturing process or assembly line is affected by the performance of a worker. This study aims at reducing the risks, efforts and fatigue related to an employee in an economical way. In this paper, initial ergonomics assessment, suggested improvements and their validation are presented for the disassembly and assembly phase activities; post engine testing. The activity selected was 8.9L engine teardown. Firstly, micro motion study of both the processes was carried out. Required data was then gathered by preparing various charts such as flow process chart, operation process chart, SIMO chart and using REBA-RULA techniques. Ergonomic assessment was done by determining the Risk Priority Score (RPS) using Humantech Software, performing iterations in the SIMO chart and analysing the REBA and RULA scores. As an improvement, a bracket-manipulator system was suggested for the 180° engine rotation process during the teardown activity. For this, the bracket was designed and checked for failures using SolidWorks and Ansys Workbench software respectively. Positive results were obtained during verification of the suggested solutions. The comparison of REBA and RULA scores for initial and modified processes indicated decrease in fatigue and efforts. The RPS was also found to reduce from 45 to 18 (60% reduction). The research reported in above methods could lead to enhancement of worker performance and productivity.