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

Quizplus · Accepted Answer

To find the normal time for element 3, first calculate the average time of the observations, then adjust for the performance rating, and finally apply the allowance factor if necessary. For element 3, the average time 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 applied to the total time and not individual elements, the normal time for element 3 before allowance is approximately 1.96 minutes.

The Data Below Represent Time Study Observations for an Assembly