Consider the system composed of four processes linked by a conveyor belt. There is no storage between these processes pictured below and market demand of 40 units per hour drives the conveyor belt. Assume that no defective units are made. Which statement is best?
A)The average time a unit spends in Process 1 is 2 and a half minutes.
B)The average time a unit spends in Process 2 is 5 minutes.
C)The flow time for a unit through the entire process is 33 minutes.
D)The flow rate through the entire process is 160 units per hour.

Question

Consider the system composed of four processes linked by a conveyor belt. There is no storage between these processes pictured below and market demand of 40 units per hour drives the conveyor belt. Assume that no defective units are made. Which statement is best? 
A)The average time a unit spends in Process 1 is 2 and a half minutes. 
B)The average time a unit spends in Process 2 is 5 minutes. 
C)The flow time for a unit through the entire process is 33 minutes. 
D)The flow rate through the entire process is 160 units per hour.

Quizplus · Accepted Answer

The flow time through the entire process can be calculated as the sum of individual process times plus the time spent on the conveyor belt.

Flow time = Process 1 time + Process 2 time + Process 3 time + Process 4 time + Conveyor time

Flow time = 2 + 6 + 12 + 12 + (40/60)

Flow time = 33 minutes

Therefore, choice C is correct. Choice A is incorrect because 2 and a half minutes is the process time for Process 1, not the time spent by a unit in that process. Choice B is incorrect because the average time a unit spends in Process 2 can be calculated as the process time of Process 2 divided by the number of arriving units, which is 24 seconds (0.4 minutes), not 5 minutes. Choice D is incorrect because the flow rate through the entire process can be calculated as the number of arriving units divided by the flow time, which is approximately 1.21 units per minute or 72.6 units per hour, not 160 units per hour.

Consider the System Composed of Four Processes Linked by a Conveyor