Question

Consider the following production process. The process consists of 38 steps and operates at a cycle time of 0.84 min/unit. Their most error prone operation is step 8. If each worker checks the work of the previous steps and there are on average roughly 116 units of inventory between step 8 and the end of the process, equally distributed across the remainder of the process, what is the average information turnaround time for a defect made at step 8 (in minutes)? (report your answer to 2 decimal places)

Answer 1

The average information turnaround time for a defect made at step 8 is 1.26 min/unit.

Step-by-step explanation:

To calculate the average information turnaround time for a defect made at step 8, we need to consider the time it takes for the defect to be identified and corrected. Since each worker checks the work of the previous steps, we can assume that the average time it takes to identify a defect at step 8 is the cycle time of the process, which is 0.84 min/unit. Once a defect is identified at step 8, it will take on average half of the cycle time to correct it. Therefore, the average time to correct a defect at step 8 is 0.42 min/unit. Now, we need to consider the average number of units in inventory between step 8 and the end of the process. Given that there are roughly 116 units of inventory equally distributed across the remainder of the process, we can assume that each step has approximately 116/30 units in inventory, since there are 30 steps after step 8. Therefore, there are roughly 116/30 = 3.87 units in inventory per step. Since each step takes 0.84 min/unit to complete, it will take an additional 3.87 units x 0.84 min/unit = 3.25 min to process the inventory after step 8. Thus, the average information turnaround time for a defect made at step 8 is the sum of the time to identify the defect (0.84 min/unit) and the time to correct the defect (0.42 min/unit), which is equal to 1.26 min/unit.