Mental Workload Evaluation of Machining Tool Operators in Manufacturing SMEs

Abstract

Human resource is an important factor that affects productivity in manufacturing companies. 37% product completion delay in a manufacturing SME in 2017 was due to human factors especially mental workload related. This study aims to measure the level of mental workload based on the type of work and shift work, using the NASA TLX. Samples were 10 male operators from five machining jobs (i.e. lathe, milling, brazing, surface grinding, and cylindrical grinding) in two working shifts. Result shows that the average mental workload on the day shift was slightly higher than the morning shift. In the morning shift, Lathe operator has the highest mental workload (MWL) with a score of 76.67, meanwhile the Brazing operators has the highest MWL on the day shift with a score of 66.67. This result indicates that mental workload on machining tool operators is classified as high. Furthermore, there are significant differences for the indicator of frustration level (FR) between shift works with a significance value of 0.09 (p <0.1). The company needs to allocate employee break time on the night shift to minimize their perceived stress level and to set work targets accordance to individual capabilities.