1. A four-step process is used to make a product. The first resource takes 8 minutes per unit, the second takes 7 minutes per unit, the third takes 2 minutes per unit, and the fourth takes 10 minutes per unit. 20% of all units have to be reworked. For that, they have to revisit the third and fourth resources. Each resource is staffed by one worker. Rework takes the same processing times as the first pass and always fixes the problem. Where is the bottleneck?
A. Resource 3
B. Resource 4
C. Resource 1
D. Resource 2
2. C&A uses a two-step process to make a part. The first step involves cutting with a machine that requires a 40-minute setup time before the production of each batch. The cutting takes 30 minutes per part. The second step is polishing the parts from cutting. The polishing takes 40 minutes per part. Assume demand is unlimited. What is the ideal batch size of the parts?
A. 8
B. 10
C. 4
D. Cannot be determined
3. C&A Printing takes 10 seconds to print a page in color, but after 500 pages, the printer must be cooled down for 15 minutes. No pages can be printed while the printer is cooling down. C&A’s demand rate is 3 pages per minute. What is the smallest batch size to ensure the process is demand-constrained?
A. Cannot be determined
B. 90
C. 64
D. 500
4. Packages arrive at a facility at a rate of 30 per hour and are processed continuously at a rate of 25 per hour. The facility is open from 8 a.m. to 4 p.m. How long does the last package wait before it is processed?
A. 1.75 hours
B. 1.20 hours
C. 1.33 hours
D. 1.60 hours
5. There are 4 servers in the checkout area. The interarrival time of customers is 2 minutes. The processing time is 5 minutes. The coefficients of variation for the arrival process and the service process are 1 and 0.85 respectively. What is the average time in queue?
A. 1 minute
B. 3 minutes
C. 4 minutes
D. 2 minutes
6. There are 3 servers in the checkout area. The interarrival time of customers is 2 minutes. The processing time is 5 minutes. The coefficients of variation for the arrival process and the service process are 1 and 0.85 respectively. What is the average number of customers that are waiting?
A. 2
B. 1
C. 4
D. 3
7. There are 4 servers in the checkout area. The interarrival time of customers is 2 minutes. The processing time is 5 minutes. What is the utilization of the servers?
A. .1
B. .4
C. 2.5
D. .625
8. Consider an Erlang loss system. The average processing time is 4 minutes. The average interarrival time is 3 minutes. How many servers does the system need to achieve a denial of service probability of no more than 0.01?
A. 6
B. 5
C. 3
D. 4
9. A hardware store rents its one wood chipper. A request for the chipper arrives every 4 days with a standard deviation of 4 days. On average clients rent the chipper for one day. If a request arrives and the chipper is not available, customers rent from another company. What percentage of demand is lost?
A. 25%
B. 80%
C. 20%
D. 0%
10. A kanban system ____________ work through the process based on _________.
A. pushes, demand
B. pulls, capacity
C. pulls, demand
D. pushes, capacity
11. What is the relationship between the number of Kanban cards in a process and the inventory level?
A. There is no relationship between the two.
B. The inventory of the process is reduced by adding more Kanban cards.
C. The inventory of the process grows with the square root of the number of Kanban cards.
D. There is no more inventory in the process than was authorized via Kanban cards