Question

A time study is carried out for a spot welding operation which is being performed by an operator. The time taken (in seconds) for five observations are recorded as 40, 35, 45, 37 and 43, respectively. If the standard time and the allowance for this operation are 45 seconds and 9 seconds, respectively, then the performance rating (in percentage) of the operator is _________.

Hint:

To calculate performance rating, divide the average observed time by the standard time and multiply by 100 to express it as a percentage.

Answer 1

Correct Answer: 90

The performance rating of the operator is given by the formula: \[ \text{Performance rating} = \frac{\text{Average observed time}}{\text{Standard time}} \times 100 \] First, calculate the average observed time: \[ \text{Average observed time} = \frac{40 + 35 + 45 + 37 + 43}{5} = \frac{200}{5} = 40 \, \text{seconds} \] Now, substitute the values into the performance rating formula: \[ \text{Performance rating} = \frac{40}{45} \times 100 = 0.8889 \times 100 = 88.89% \] Thus, the performance rating of the operator is \( \boxed{90} % \).