課程名稱︰作業管理
課程性質︰必修
課程教師︰陳文華
開課學院：管理學院
開課系所︰工管系企管組
考試日期（年月日）︰2007/1/17
考試時限（分鐘）：09:10-12:20
是否需發放獎勵金：是
（如未明確表示，則不予發放）
試題 :
I. Multiple Choice-Concept (46%, 2 points each)
1. Use the process flow diagram to determine which of these events has the
greatest net benefit.
Station A Station B Station C Station D
1 worker → 1 worker → 1 worker → 1 worker
8 minutes 7 units/hr 6 units/hr 9 minutes
a. reducing the flow time at Station A from 8 to 7 minutes.
b. increasing the capacity at Station B to 8 units per hour.
c. increasing the capacity at Station C to 7 units per hour.
d. reducing the flow time at Station D from 9 to 8 minutes.
2. The third step in Theory of Constraints application," subordinate all
other decisions to Step 2",means that:
a. the analyst should wait for authorization before proceeding with any
system-wide changes.
b. the analyst should schedule non-bottleneck processes to support the
bottleneck schedule.
c. the analyst should seek to increase capacity of only the bottleneck
resources.
d. the analyst should seek to increase capacity of both bottleneck and
non-bottleneck resources.
3. Which one of the following statements concerning capacity cushions is best?
a. Small-capacity cushions are used extensively in capital-intensive firms.
b. Large-capacity cushions are used more often when future demand is level
and known.
c. Capacity cushions are used primarily in manufacturing organizations, not
in service organizations.
d. Small cushions are used in organizations where the products and services
produced often change.
4. Lean systems try to:
a. produce product in anticipation of demand.
b. organize production in large lots to minimize the number of setups.
c. reduce the labor content in all process.
d. maximize the value added by of each of their activities.
5. The lean system concept will not work without the proper environment.
Which one of the following characteristics is most common to firms that have
successfully implemented a lean system?
a. Uniform assembly schedules.
b. Specialized workforce.
c. High rates if machine failures.
d. Longer setup times.
6. Companies using lean systems generally have:
a. many suppliers to ensure that material shortages never occur.
b. suppliers that are located nearby to decrease delivery lead time.
c. suppliers that are willing to accept short-term contracts.
d. suppliers who are low-cost producers.
7. The basic purpose of supply chain management is to:
a. create an exclusive set of suppliers who will not supply your competitors.
b. link your customers together so that the flow of materials remains under
control.
c. synchronize the operations of all suppliers with those of purchasing,
production,distribution,and customers.
d. reduce the inventory by proper selection of customers and transportation
modes.
8. Which of the following changes would decrease the likelihood of the
bullwhip effect?
a. Changing the mix of items in an order.
b. Sending partial shipments of an order.
c. Instituting a policy of no discounts or promotions.
d. Sending late deliveries of an order.
9. Which one of the following statements represents a benefit of centralized
buying?
a. Local managers have more control over their business.
b. Purchases and production schedules are meshed more easily.
c. Purchasing lead times may be shorter.
d. Increased buying power can result in significant savings in purchasing
costs.
10. An efficient supply chain should be preferred when:
a. demand is highly predictable.
b. product variety is high.
c. competitive priority is customization.
d. demand is unpredictable.
11.Padco averages ＄15 million worth of inventory in all of its worldwide
locations. They operate 51 weeks a year and each week average ＄3 million in
sales(at cost).Their inventory turnover is:
a. 1.13 turns.
b. 5 turns.
c. 10.2 turns.
d. 17 turns.
12. A responsive supply chain typically has:
a. a low capacity cushion.
b. high inventory turns.
c. supply chain partners that emphasize low prices.
d. supply chain partners that emphasize volume flexibility.
13. A somewhat successful computer manufacturer makes a generic computer in
five exciting colors. Once orders are received, the computer guts are encased
in the customer's choice of colored case. This approach is known as:
a. channel assembly.
b. postponement.
c. strategic sourcing.
d. strategic production.
14. Norman Regional Hospital always kept a few extra heart catheters on hand
because when a patient showed up that needed one, they really needed one.
This is a prime example of:
a. anticipation inventory.
b. pipeline inventory.
c. safety stock inventory.
d. cycle inventory.
15. A company operating under an EOQ policy enjoys rising annual demand for
their products for three consecutive years. During this time their holding
cost and ordering cost remain constant. Which statement is best?
a. Their order quantity will rise but the time between orders will fall.
b. Their order quantity will fall and so will the time between orders.
c. Their order quantity will fall but the time between orders will rise.
d. Their order quantity will rise and so will the time between orders.
16. An inventory system answers two important questions: when to order and
how much to order. Which of the following statements correctly explains how a
Q system (continuous review system) or a P system (periodic review system)
answers these questions?
a. Under a Q system, a fixed quantity is ordered every P time period.
b. Under a Q system, an order is placed to replenish the inventory position
up to the target level T when the inventory position reaches the reorder
point R.
c. Under a P system, a fixed quantity Q is ordered when the inventory
position reaches the reorder point R.
d. Under a P system, an order is placed to replenish the inventory position
up to the target level T every P time periods.
17. Which one of the following statements represents an advantage of the P
system over the Q system?
a. Less safety stock is carried to achieve the same service level.
b. The replenishment intervals can be more easily individualized for items.
c. Orders can be more easily combined to the same supplier.
d. A P system is more suitable for quantity discounts and capacity
limitations.
18.A neighborhood sportswear store sells a pair of Victoria sneakers for ＄
40.Due to the recent fitness craze, these shoes are in high demand:50 pairs
of shoes are sold per week. The ordering cost is ＄20 per order, and the
annual holding cost is 20％ of selling price. If the store operates 52 weeks
a year, what can you say about the current lot size of 235?
a. Too large.
b. Too small.
c. Just right.
d. Cannot tell from the information given.
19. Which one of the following statements about forecasting is FALSE?
a. To achieve the objective of developing a useful forecast from the
information at hand, the forecaster must select the appropriate technique.
This choice sometimes involves a trade-off between forecast accuracy and cost.
b. Three general types of forecasting techniques are used for demand
forecasting: time-series analysis, casual methods, and judgment methods.
c. Time series express the relationship between the factor to be forecast and
related factors such as promotional campaigns, and economic conditions.
d. A time series is a list of repeated observations of phenomenon, such as
demand, arranged in the order in which they actually occurred.
20. Which of the following statements regarding time-series methods is FALSE?
a. A naive forecast is identical to a simple moving average of one period.
b. Exponential smoothing with an alpha equal to 1.00 is identical to a naive
forecast.
c. A weighted moving average with weights of 0.5 and 0.5 is identical to a
simple moving average of two periods.
d. A simple moving average of three periods is identical to exponential
smoothing with an alpha equal to 0.33.
21. Assume that a time-series forecast is generated for future demand and
subquently it is observed that the forecast method did not accurately predict
the actual demand.Specifically,the forecast errors were found to be:
Mean absolute percent error=10％
Cumulative sum of forecast errors=0％
Which one of the statement concerning this forecast is TRUE?
a. The forecast has no bias but has positive standard deviation of errors.
b. The forecast has a positive bias and a standard deviation of errors equal
to zero.
c. The forecast has no bias and has a standard deviation of errors equal to
zero.
d. The forecast has a positive bias and a positive standard deviation of
errors.
22. A line-balancing solution has been developed for the assembly line for
fertilizer spreaders at Green Grass,Inc. The desired output rate of 30
spreaders per hour will be achieved. The sum of times for all tasks performed
on the line is 1200 seconds for each spreader assembled. This is the total
productive time. Which of the following statements must be true?
a. The cycle time is 30 seconds per spreader.
b. The theoretical minimum number of stations is 10.
c. If the solution calls for 12 stations, the efficiency is 80％.
d. If the solution calls for 11 stations, the efficiency is 80％
23. A company uses a kanban system. The demand for part A over an eight-hour
production day is 1000 units. The average waiting time for a container of
parts is 45 minutes. The Processing time for a container of part A is 2
hours, and a container holds 70 units. How many kanban containers would be
required if a 15％ policy variable is used?
a. 6 or fewer.
b. 7 or 8.
c. 15 to 20.
d. 20 or more.
II. Problem Solving (24％)
Table 1
The following information is given about an assembly line. The desired output
rate is 90 units per hour.
Work Element Time (sec) Immediate Predecessor(s)
A 10 --
B 5 A
C 15 A
D 20 B
E 12 B
F 14 C, E
G 8 D
H 20 F, G
1. (3％) Based on Table 1. What is the fewest number of workstations that
your need?
a. Two stations.
b. Three stations.
c. Four stations.
d. More than four stations.
2. (3％) Based on Table 1. Suppose that the desired output rate is increased
to 120 units per hour and a solution has been found that has four
workstations. What is the efficiency of this new assembly line?
a. Less than 80％.
b. Between 80％ and 85％.
c. Between 85％ and 90％.
d. More than 90％.
3. (5％) The single milling machine at Stout Manufacturing was severely
overloaded last year. The plant operates 8 hours/day, 5 days/week, and 50
weeks/year. Management prefers a capacity cushion of 15 percent. Two major
types of products are routed through the milling machine. The annual demand
for product A is 3000 units and 2000 units for product B. The batch size for
A is 20 units and 40 units for B. The standard processing time for A is 0.5
hours/unit and 0.8 for B. How many new milling machines are required if Stout
does not resort to any short-term capacity options?
4. (5％) A company makes four products that have the following
characteristics: Product A sells for ＄75 but needs ＄20 of materials and ＄
20 of labor to produce; Product B sells for ＄ 90 but needs ＄ 45 of material
and ＄20 of labor to produce; Product C sells for ＄110 but needs ＄50 of
materials and ＄30 of labor to produce; Product D sells for ＄135 but needs ＄
75 of materials and ＄40 of labor to produce. The processing requirements for
each product on each of the four machines are shown in the table.
Processing Time (min/unit)
Work Center A B C D
W 8 4 12 10
X 12 9 10 6
Y 8 12 14 5
Z 10 9 5 5
Work centers W, X, Y, and Z are available for 40 hours per week and have no
setup time when switching between products. Market demand is 50 As, 60 Bs, 70
Cs, and 80 Ds per week. What is the optimal product mix?
5. (8％) A store has collected the following information on one of its
products:
Demand=10000 units/year
Standard deviation of weekly demand=25 units
Ordering costs=＄30/order
Holding costs=＄4/unit/year
Cycle-service level=95％(z for 90％=1.64)
Lead-time=2 weeks
Number of weeks per year=50 weeks
a. If a firm uses the continuous review system to control the inventory, what
would be the order quantity and reorder point?
b. The firm decided to change to the periodic review system to control the
item's inventory. For the most recent review, an inventory clerk checked the
inventory of this item and found 200 units. There were no scheduled receipts
or vackorders at the time. How many units should be ordered? (HINT: Use the
EOQ model to derive P, the time between reviews.)
III. Case Study (25％) Due Date: 01/21 (Case: Wolf Motors, Chapter 10,
Operations Management, Processes and value chain, 8th edition,
Krajewski.Ritzman.Malhotra )
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