improve the productivity of assembly workstation. Time study is working measurement technique consisting time measurement of worker that doing jobs in normal pace. Performance rating and allowance are added into observed time to calculate standard time. Index Terms— Productivity, Work measurement, Time Study, Standard Time. In a time study, personal time, fatigue, and unavoidable delays (PFD) during the typical work day are accounted for in the allowance factor. true. If OT = the mean observed time, PRF = the performance rating factor, F = the frequency of occurrence, and PFD = the percentage allowance adjustment based on job time, the formula to compute the Performance rating factor: The pace the person is working at. 90% is working slower than normal, 110% is working faster than normal, 100% is normal. This factor is calculated by an experienced worker who is trained to observe and determine the rating. Personal, fatigue, and delay (PFD) allowance. The standard time can then be calculated by using: