Chapter 12

If setup costs are reduced by substantial reductions in setup time, the production order quantity is also reduced.

True

In the production order quantity (POQ) model, inventory does not arrive in a single moment but flows in at a steady rate, resulting in a larger lot size than in an otherwise identical EOQ problem.

True

If daily demand is normally distributed with a mean of 15 and standard deviation of 5, and lead time is constant at 4 days, 90 percent service level will require safety stock of approximately a. 7 units b. 10 units c. 13 units d. 16 units e. 26 units

c. 13 units

At the economic order quantity, holding costs are equal to purchasing costs.

False

In the quantity discount model, the cost of acquiring goods (product cost) is not a factor in determining lot size.

False

The EOQ model is best suited for items whose demand is dependent on other products.

False

In the simple EOQ model, if the carrying cost were to double, the EOQ would also double.

False

A product has demand of 4000 units per year. Ordering cost is $20 and holding cost is $4 per unit per year. The EOQ model is appropriate. The cost-minimizing solution for this product will cost _____ per year in total annual inventory costs. a. $400 b. $800 c. $1200 d. zero; this is a class C item e. cannot be determined because unit price is not known

b. $800

A product has demand of 4000 units per year. Ordering cost is $20 and holding cost is $4 per unit per year. The cost-minimizing solution for this product is to order a. all 4000 units at one time b. 200 units per order c. every 20 days d. 10 times per year e. none of the above

b. 200 units per order

A production order quantity problem has daily demand rate = 10 and daily production rate = 50. The production order quantity for this problem is approximately 612 units. The average inventory for this problem is approximately a. 61 b. 245 c. 300 d. 306 e. 490

b. 245

For a certain item, the cost-minimizing order quantity obtained with the basic EOQ model was 200 units and the total annual inventory (carrying and setup) cost was $600. The inventory carrying cost per unit per year for this item is a. $1.50 b. $2.00 c. $3.00 d. $150.00 e. not enough data to determine

c. $3.00

A certain type of computer costs $1,000, and the annual holding cost is 25%. Annual demand is 10,000 units, and the order cost is $150 per order. What is the approximate economic order quantity? a. 16 b. 70 c. 110 d. 183 e. 600

c. 110

In the basic EOQ model, if D=6000 per year, S=$100, H=$5 per unit per month, the economic order quantity is approximately a. 24 b. 100 c. 141 d. 490 e. 600

c. 141

In a safety stock problem where both demand and lead time are variable, demand averages 150 units per day with a daily standard deviation of 16, and lead time averages 5 days with a standard deviation of 1 day. The standard deviation of demand during lead time is approximately a. 15 units b. 100 units c. 154 units d. 500 units e. 13,125 units

c. 154 units

The two most basic inventory questions answered by the typical inventory model are a. timing and cost of orders b. quantity and cost of orders c. timing and quantity of orders d. order quantity and service level e. ordering cost and carrying cost

c. timing and quantity of orders

Most inventory models attempt to minimize a. the likelihood of a stockout b. the number of items ordered c. total inventory based costs d. the number of orders placed e. the safety stock

c. total inventory based costs

In the simple EOQ model, if annual demand were to increase, the EOQ would increase proportionately.

False

Safety stock in inventory systems depends only on the average demand during the lead time.

False

In the quantity discount model, it is possible to have a cost-minimizing solution where annual ordering costs do not equal annual carrying costs.

True

Service level is the complement of the probability of a stockout.

True

The reorder point is the inventory level at which action is taken to replenish the stocked item.

True

Units of safety stock are additions to the reorder point that allow for variability in the rate of demand, the length of lead time, or both.

True

A specific product has demand during lead time of 100 units, with a standard deviation of 25 units. What safety stock (approximately) provides a 95% service level? a. 41 b. 55 c. 133 d. 140 e. 165

a. 41

The fixed-period inventory model requires more safety stock than the fixed-quantity models because a. a stockout can occur during the review period as well as during the lead time b. this model is used for products that have large standard deviations of demand c. this model is used for products that require very high service levels d. replenishment is not instantaneous e. setup costs and holding costs are large

a. a stockout can occur during the review period as well as during the lead time

In the basic EOQ model, if the cost of placing an order doubles, and all other values remain constant, the EOQ will a. increase by about 41% b. increase by 100% c. increase by 200% d. increase, but more data is needed to say by how much e. either increase or decrease

a. increase by about 41%

An inventory decision rule states "when the inventory level goes down to 14 gearboxes, 100 gearboxes will be ordered." Which of the following statements is true? a. One hundred is the reorder point, and 14 is the order quantity. b. Fourteen is the reorder point, and 100 is the order quantity. c. The number 100 is a function of demand during lead time. d. Fourteen is the safety stock, and 100 is the reorder point. e. None of the above is true.

b. Fourteen is the reorder point, and 100 is the order quantity.

Which of the following statements regarding the production order quantity model is true? a. It applies only to items produced in the firm's own production departments. b. It relaxes the assumption that all the order quantity is received at one time. c. It relaxes the assumption that the demand rate is constant. d. It minimizes the total production costs. e. It minimizes inventory.

b. It relaxes the assumption that all the order quantity is received at one time.

A product whose EOQ is 400 experiences a 50% increase in demand. The new EOQ is a. unchanged product whose EOQ is 400 experiences a 50% increase in demand. The new EOQ is b. increased by less than 50% c. increased by 50% d. increased by more than 50% e. cannot be determined

b. increased by less than 50%

A product whose EOQ is 40 experiences a decrease in ordering cost from $90 per order to $10. The revised EOQ is a. three times as large b. one-third as large c. nine times as large d. one-ninth as large e. cannot be determined

b. one-third as large

The assumptions of the production order quantity model are met in a situation where annual demand is 3650 units, setup cost is $50, holding cost is $12 per unit per year, the daily demand rate is 10 and the daily production rate is 100. The production order quantity for this problem is approximately a. 139 b. 174 c. 184 d. 365 e. 548

c. 184

If daily demand is constant at 10 units per day, and lead time averages 12 days with a standard deviation of 3 days, 95 percent service requires a safety stock of approximately a. 28 units b. 30 units c. 49 units d. 59 units e. 114 units

c. 49 units

If the actual order quantity is the economic order quantity in a problem that meets the assumptions of the economic order quantity model shown below, the average amount of inventory on hand Q=√[(2DS)/H] a. is smaller the smaller is the holding cost per unit b. is zero c. is one-half of the economic order quantity d. is affected by the amount of product cost e. All of the above are true.

c. is one-half of the economic order quantity

Which of these statements about the production order quantity model is false? a. The production order quantity model is appropriate when the assumptions of the basic EOQ model are met, except that receipt is noninstantaneous. b. Because receipt is noninstantaneous, some units are used immediately, not stored in inventory. c. Average inventory is less than one-half of the production order quantity. d. All else equal, the smaller the ratio of demand rate to production rate, the larger is the production order quantity. e. None of the above is false.

d. All else equal, the smaller the ratio of demand rate to production rate, the larger is the production order quantity

Which of the following statements about the basic EOQ model is false? a. If the setup cost were to decrease, the EOQ would fall. b. If annual demand were to increase, the EOQ would increase. c. If the ordering cost were to increase, the EOQ would rise. d. If annual demand were to double, the EOQ would also double. e. All of the above statements are true.

d. If annual demand were to double, the EOQ would also double.

Which of the following is not an assumption of the economic order quantity model shown below? Q=√[(2DS)/H] a. Demand is known, constant, and independent. b. Lead time is known and constant. c. Quantity discounts are not possible. d. Production and use can occur simultaneously. e. The only variable costs are setup cost and holding (or carrying) cost.

d. Production and use can occur simultaneously.

Which of the following statements about quantity discounts is false? a. The cost-minimizing solution may or may not be where annual holding costs equal annual ordering costs. b. In inventory management, item cost becomes relevant to inventory decisions only when a quantity discount is available. c. If carrying costs are expressed as a percentage of value, EOQ is larger at each lower price in the discount schedule. d. The larger annual demand, the less attractive a discount schedule will be. e. The smaller the ordering cost, the less attractive a discount schedule will be.

d. The larger annual demand, the less attractive a discount schedule will be.

If demand is not uniform and constant, then stockout risks can be controlled by a. increasing the EOQ b. placing an extra order c. raising the selling price to reduce demand d. adding safety stock e. reducing the reorder point

d. adding safety stock

The purpose of safety stock is to a. replace failed units with good ones b. eliminate the possibility of a stockout c. eliminate the likelihood of a stockout due to erroneous inventory tally d. control the likelihood of a stockout due to the variability of demand during lead time e. protect the firm from a sudden decrease in demand

d. control the likelihood of a stockout due to the variability of demand during lead time

The EOQ model with quantity discounts attempts to determine a. what is the lowest amount of inventory necessary to satisfy a certain service level b. what is the lowest purchasing price c. whether to use fixed-quantity or fixed-period order policy d. how many units should be ordered e. what is the shortest lead time

d. how many units should be ordered

The proper quantity of safety stock is typically determined by a. minimizing an expected stockout cost b. carrying sufficient safety stock so as to eliminate all stockouts c. meeting 95% of all demands d. setting the level of safety stock so that a given stockout risk is not exceeded e. minimizing total costs

d. setting the level of safety stock so that a given stockout risk is not exceeded

The primary purpose of the basic economic order quantity model shown below is Q=√[(2DS)/H] a. to calculate the reorder point, so that replenishments take place at the proper time b. to minimize the sum of carrying cost and holding cost c. to maximize the customer service level d. to minimize the sum of setup cost and holding cost e. to calculate the optimum safety stock

d. to minimize the sum of setup cost and holding cost

Which of the following statements regarding the reorder point is true? a. The reorder point is that quantity that triggers an action to restock an item. b. There is a reorder point even if lead time and demand during lead time are constant. c. The reorder point is larger than d x L if safety stock is present. d. The fixed-period model has no reorder point. e. All of the above are true.

e. All of the above are true.

Which of the following statements about the basic EOQ model is true? a. If the ordering cost were to double, the EOQ would rise. b. If annual demand were to double, the EOQ would increase. c. If the carrying cost were to increase, the EOQ would fall. d. If annual demand were to double, the number of orders per year would increase. e. All of the above statements are true.

e. All of the above statements are true.

If the standard deviation of demand is six per week, demand is 50 per week, and the desired service level is 95%, approximately what is the statistical safety stock? a. 8 units b. 10 units c. 16 units d. 64 units e. cannot be determined without lead time data

e. cannot be determined without lead time data

Demand for dishwasher water pumps is 8 per day. The standard deviation of demand is 3 per day, and the order lead time is four days. The service level is 95%. What should the reorder point be? a. about 18 b. about 24 c. about 32 d. about 38 e. more than 40

e. more than 40

Which category of inventory holding costs is much higher than average for rapid-change industries such as PCs and cell phones? a. housing costs b. material handling costs c. labor cost d. parts cost e. pilferage, scrap, and obsolescence

e. pilferage, scrap, and obsolescence