An Evaluation of Muscle Workload by ISO / TS 20646-1: A Case Study in Maintenance Department of Bevpro Asia Company

Abstract

This study aims to evaluate local muscle workloads in maintenance department by using ISO/TS 2064-1 principle (Ergonomic Improvement of the Procedure for Local Muscular Workloads) included Annex-B: a survey to identify the hazards associated with the work load of the muscle, Annex-C: a survey to improve the working environment, and Annex-D: using a questionnaire to survey the work load of the muscle, to survey the work load of muscle and body part discomfort and using the revised NIOSH lifting equation to determine the recommended weight of lifting. Subjects are 8 male workers in maintenance department. The survey showed that workers lifted 12 broken machines per day on average from the floor to the work station. The height of work station is 40 centimeters. The weight of the machine is about 67 kilograms. The revised NIOSH equation showed that this weight is too heavy to lift by hand. Results from Annex B showed that 75 percent of workers have unequal workloads and all task required excess force to continue. There are 3 results from Annex C including workers needed material handing example of hydraulic ramp to moving the heavy machines, the height of the work station has to be adjustable to a suitable height so workers can work in the way not to bend their torso, and temperature at the work station should be reduced. Results from Annex D showed that workers experienced lower back pain. The average score is 3.87 on average. The lower back pain score is 12.5 on average means most injuries and upper arm pain score is 8 on averages means workers feel severe pain. These score means the workers have an intermediately risk and need to improve their work. Therefore, this study has improved the work station by using the new designed work station with suitable height at 70 centimeters. When this height plus the height of machine at 45 centimeters is equal to 115 centimeters. The height at 115 centimeters is in workers’ elbow height so workers can work with this height without bending their torso. Furthermore, the hydraulic ramp is used to lift the broken machines instead of manual lifting. Air conditioner also installed at the workplace to temperature not above $27^{\circ}\mathrm{C}$. After a 3-month trial, the results from all improvements showed that workers feel satisfied with the work improvements and do not need to adjust further. In addition, the average score from Annex D decreased to 1.58, which is located in low injury criteria