Calculating base period is one of the crucial steps in achieving the standard time values and ratings are used for
calculating the base period. The ratings of an element are given instantly during observation. The rating process is
the step of study that requires extensive experience. The most important limitation on this research is “the difficulty
in immediately determining which work pace is standard and which is below or above standard pace”. Another
limitation is the workers who know they are being observed; they sometimes tend to work slower than their actual
performance.