The Influence of Fatigue on the Performance of Machinist : The Moderating Role of Demographic Characteristics

This study aims to examine the effect of fatigue levels on the performance of machinist in Operational Area 1 Jakarta, with demographic characteristics namely age and length of service as moderating variables. A quantitative approach using a survey method was employed, involving 285 respondents selected through purposive sampling. Data were collected using standardized and validated instruments, namely the Individual Work Performance Questionnaire and the Fatigue Severity Scale. Data analysis was conducted using SPSS version 30. The results indicate that fatigue, age, and length of service simultaneously had a significant negative effect on performance, with a significance value of 0.001 < 0.05. Fatigue had a significant negative effect on performance, with a regression coefficient of -0.501 and a probability value of 0.001 < 0.05. Age also had a significant negative effect on performance, with a regression coefficient of -0.268 and a probability value of 0.019 < 0.05. Likewise, length of service showed a significant negative effect, with a regression coefficient of -0.318 and a probability value of 0.002 < 0.05. However, age and length of service were not found to moderate the relationship between fatigue and performance. These findings highlight the importance of fatigue management in maintaining performance, especially in occupations that impact public transportation safety, such as the railway sector. Theoretically, this study contributes to the field of industrial and organizational psychology, particularly in understanding the psychological and demographic factors that influence performance requiring high levels of concentration and physical endurance in the workplace.