MEM Operations Management 2

Question 1

A factory produces 500 units per day with a defect rate of 4%. After implementing Six Sigma controls, the defect rate drops to 0.5%. What is the daily reduction in defective units?

Accepted Answer

17.5 units

Answer

Original defects = 500 × 0.04 = 20; new defects = 500 × 0.005 = 2.5; reduction = 17.5 units per day.

Question 2

Which scheduling rule minimizes the average number of jobs in the system when processing times are known?

Accepted Answer

Shortest Processing Time (SPT)

Answer

SPT minimizes mean flow time and average work-in-process, thereby minimizing the average number of jobs in the system.

Question 3

In a Theory of Constraints analysis, the constraint operation processes 80 units/hour while all other stations process 100+ units/hour. Demand is 90 units/hour. What is the system throughput?

Accepted Answer

80 units/hour

Answer

System throughput is governed by the bottleneck (constraint), so output equals 80 units/hour regardless of demand.

Question 4

A company uses a periodic review inventory system with a review period of 2 weeks and a lead time of 1 week. Safety stock is calculated based on how many weeks of demand variability?

Accepted Answer

3 weeks

Answer

In a periodic review system, safety stock covers variability during the review period plus lead time (2 + 1 = 3 weeks).

Question 5

Which lean metric directly measures the ratio of value-added time to total lead time in a process?

Accepted Answer

Process cycle efficiency (PCE)

Answer

PCE = value-added time / total lead time, and a world-class PCE is typically above 25%.

MEM - Master of Engineering Management Practice Test

MEM - Master of Engineering Management Practice Test

MEM Operations Management 2