Quantitative Methods Exam Ch 13-15

For the EOQ model, which of the following relationships is incorrect?

As the order quantity increases, annual ordering cost increases.

Inventory models in which the rate of demand is constant are called

deterministic models.

PERT and CPM

have been combined to develop a procedure that uses the best of each.

The arrival rate in queuing formulas is expressed as

the mean number of arrivals per time period.

Which of the following is not implied when average inventory is Q/2, where Q is the order quantity?

Backorders are permitted.

A path through a project network must reach every node.

False

Crashing refers to an unanticipated delay in a critical path activity that causes the total time to exceed its limit.

False

For all waiting lines, P0 + Pw = 1.

False

The time between placing orders is the lead time.

False

When quantity discounts are available, order an amount from the highest discount category.

False

For many waiting line situations, the arrivals occur randomly and independently of other arrivals and it has been found that a good description of the arrival pattern is provided by

a Poisson probability distribution.

To determine how to crash activity times

a.realize that new paths may become critical. b.normal activity costs and costs under maximum crashing must be known. c.shortest times with crashing must be known. *****d.All of the alternatives are true.*****

Safety stock

depends on the variability of demand during lead time.

Activities G, P, and R are the immediate predecessors for activity W. If the earliest finish times for the three are 12, 15, and 10, then the earliest start time for W

is 15.

The objective of the EOQ with quantity discounts model is to

minimize the sum of annual carrying, holding, and purchase costs.

Arcs in a project network indicate

precedence relationships.

In the single-period inventory model with probabilistic demand,

probabilities are used to calculate expected losses.

Adding more channels always improves the operating characteristics of the waiting line and reduces the waiting cost.

true

In a waiting line situation, arrivals occur, on average, every 10 minutes, and 10 units can be received every hour. What are λ and μ?

λ = 6, μ = 10

Operating characteristics formulas for the single-channel queue do NOT require

λ ≥ μ.

​The machine repair problem is an application of the M/M/1 model with

​a finite calling population.

​A critical activity is

​an activity with zero slack.

What costs should a manager consider when setting order points?​

​carrying costs and stockout costs

In CPM, for activities with more than one immediate predecessor activity, which of the following is used to compute its earliest finish (EF) time​

​largest EF among the immediate predecessors