Question

In work-study (time and motion study) applied to mining operations, what is the primary purpose of a “rating factor”?

• A. To adjust the observed time to standard time based on worker's performance level
• B. To calculate machine availability
• C. To determine labour cost per ton
• D. To measure drill penetration rate

Hint:

In work measurement, \[ \boxed{ \text{Normal Time} = \text{Observed Time} \times \text{Performance Rating}. } \] Standard Time is obtained after adding allowances.

Answer 1

The Correct Option is A

Step 1: Recall the meaning of rating factor. In time study, the rating factor measures the worker's performance relative to a standard performance.

Step 2: State its purpose. The observed time is adjusted using the performance rating to obtain the normal time, which is later used to determine the standard time. Thus, the rating factor is used \[ \boxed{\text{To adjust the observed time to standard time based on the worker's performance level}.} \] Hence, \[ \boxed{(A)} \] is the correct answer.