The data below represent time study observations for an assembly operation. Assume a 7% allowance factor. What is the normal time for element 3?
$$\begin{array} { | c | c | c | c | c | c | c | }
\hline & & { \text { Observations (times in minutes) } } \
\hline \text { Element } & \text { Performance Rating } & 1 & 2 & 3 & 4 & 5 \
\hline 1 & 100 \% & 1.5 & 1.6 & 1.4 & 1.5 & 1.5 \
\hline 2 & 90 \% & 2.3 & 2.2 & 2.1 & 2.2 & 2.4 \
\hline 3 & 115 \% & 1.7 & 1.9 & 1.9 & 1.4 & 1.6 \
\hline 4 & 100 \% & 3.5 & 3.6 & 3.6 & 3.6 & 3.2 \
\hline
\end{array}$$
A) 1.7 min.
B) 1.96 min.
C) 2.11 min.
D) 10.1 min.
E) 11.2 min.

Question

The data below represent time study observations for an assembly operation. Assume a 7% allowance factor. What is the normal time for element 3?
$$\begin{array} { | c | c | c | c | c | c | c | } 
\hline & & { \text { Observations (times in minutes) } } \
\hline \text { Element } & \text { Performance Rating } & 1 & 2 & 3 & 4 & 5 \
\hline 1 & 100 \% & 1.5 & 1.6 & 1.4 & 1.5 & 1.5 \
\hline 2 & 90 \% & 2.3 & 2.2 & 2.1 & 2.2 & 2.4 \
\hline 3 & 115 \% & 1.7 & 1.9 & 1.9 & 1.4 & 1.6 \
\hline 4 & 100 \% & 3.5 & 3.6 & 3.6 & 3.6 & 3.2 \
\hline
\end{array}$$
A) 1.7 min.
B) 1.96 min.
C) 2.11 min.
D) 10.1 min.
E) 11.2 min.

Quizplus · Accepted Answer

To calculate the normal time for element 3, first find the average of the observations, then adjust for the performance rating, and finally apply the allowance factor. The average time for element 3 is (1.7 + 1.9 + 1.9 + 1.4 + 1.6) / 5 = 1.7 minutes. Adjusted for the performance rating of 115%, the time is 1.7 * 1.15 = 1.955 minutes. Since the allowance factor is not applied to individual elements but to the total time, the normal time for element 3 before allowance is approximately 1.96 minutes.

The Data Below Represent Time Study Observations for an Assembly