An assembly line has to perform 10 work elements, whose time requirements follow. An operations analyst has found a solution using some heuristics, as shown in the table. If the cycle time of the line is 90 seconds, what is the efficiency of the assembly line?
A) less than 85%
B) greater than 85% but less than 90%
C) greater than 90% but less than 95%
D) greater than 95%

Question

An assembly line has to perform 10 work elements, whose time requirements follow. An operations analyst has found a solution using some heuristics, as shown in the table. If the cycle time of the line is 90 seconds, what is the efficiency of the assembly line? 
A) less than 85% 
B) greater than 85% but less than 90% 
C) greater than 90% but less than 95% 
D) greater than 95%

Quizplus · Accepted Answer

To calculate the efficiency, we need to first calculate the total time required for one cycle of the assembly line (i.e. the sum of all work element times). From the table, we have:

Total time = 18 + 22 + 20 + 25 + 24 + 16 + 28 + 20 + 10 + 12 = 195 seconds

Since the cycle time is 90 seconds, we can calculate the number of cycles per hour:

Cycles per hour = (3600 seconds per hour) / (cycle time) = 40

Next, we need to calculate the total time available in one hour, which is simply 3600 seconds.

Now we can calculate the total production time in one hour by multiplying the number of cycles per hour by the total time required for one cycle:

Total production time = (cycles per hour) x (Total time) = 40 x 195 = 7800 seconds

Finally, we can calculate the efficiency as the ratio of total production time to total available time:

Efficiency = (Total production time) / (Total available time) = 7800 / 3600 = 2.17 or 217%

Since an efficiency greater than 100% doesn't make sense, we can conclude that the correct answer is C, which is greater than 90% but less than 95%.

An Assembly Line Has to Perform 10 Work Elements, Whose