FINAL

Infeasibility means that the number of solutions to the linear programming models that satisfies all the problem's constraints is

0

A suburban specialty restaurant has developed a single drive-thru window. Customers order, pay, and pick up their food at the same window. Arrivals follow a Poisson distribution while service times follow an exponential distribution. If the average number of arrivals is 6 per hour and the service rate is 2 every 15 minutes, what proportion of the time is the server busy (utilized)?

0.75

Consider the following linear programming problem: Maximize 4X + 10Y Subject to: 3X + 4Y ≤ 480 4X + 2Y ≤ 360 all variables ≥ 0 The feasible corner points are (48,84), (0,120), (0,0), (90,0). What is the maximum possible value for the objective function?

1200

Given an activity's optimistic, most likely, and pessimistic time estimates of 4, 14, and 18 days respectively, compute the PERT expected activity time for this activity.

13

Daily demand for newspapers for the last 10 days has been as follows (listed from oldest to newest): 12, 13, 16, 15, 12, 18, 14, 12, 13, 15. Forecast sales for the next day (i.e. day 11) using a two-day moving average.

14

The following represents a project with known activity times. All times are in weeks. Activity Immediate Predecessor Time A - 4 B - 3 C A 2 D B 7 E C, D 4 F B 5 Using the data in Table above, what is the minimum possible time required for completing the project?

14

Consider a project that has an expected completion time of 30 weeks and a standard deviation of 6 weeks. What is the probability that the project will be take more than 42 weeks? (Round answer) 68%

2

Calculate MAD for the following forecast versus actual sales figures.

2.5

Candy Incorporated stocks bubble gum game cards, an item that has a normally distributed demand during the reorder period with a mean of 12 dozen boxes and a standard deviation of 2 dozen boxes. If it is desirable to experience a stockout only 10 percent of the time, what is the appropriate safety stock?

2.56

The annual demand for a product has been projected at 2,000 units. This demand is assumed to be constant throughout the year. The ordering cost is $20 per order, and the holding cost is 20 percent of the purchase cost. Currently, the purchase cost is $40 per unit. There are 250 working days per year. Whenever an order is placed, it is known that the entire order will arrive on a truck in 6 days. How many units should the company order each time an order is placed if the company wishes to minimize total inventory cost?*****

5 days

How long can activity C be delayed without delaying the completion of the project?

6

The annual demand of a certain item is 5400 units and the computed EOQ is 900 units. How many orders do they have to make per year?

6

At an automatic car wash, cars arrive randomly at a rate of 7 cars every 30 minutes. The car wash takes exactly 4 minutes. On average, what would the length of the line be?

6.533

At a local fast food joint, cars arrive randomly at a rate of 12 every 30 minutes. Service times are random (exponential) and average 2 minutes per arrival. The average time in the queue for each arrival is

8 minutes

Which of the following is a general rule for crashing activities?

Crash activities with zero slack.

Which of the following statements is true about r2?

It is also called the coefficient of determination

EVPI (Expected Value of Perfect Information) is a measure of the maximum value of additional information.

True

On a practical note-if we are using waiting line analysis to study cars passing through a single tollbooth, reneging is probably not an issue.

false

Slack is the time an activity can be delayed without impacting the completion time of the project.****

false

The variance of the project completion time is equal to the sum of the variances of all the activities.

false

The critical path of a network is the

longest time path through the network

Which of the following factors is (are) not included in ordering cost?

obsolence

A constraint that does not affect the feasible region is a

redundant constraint

Extra inventory that is used to avoid stockouts is known as

safety stock

The term queue discipline describes the

sequence in which members of the queue are serviced.

An M│M│3 model has Poisson arrivals, exponential service times, and two channels.

treu

One difficulty in waiting line analysis is that it is sometimes difficult to place a value on customer waiting time.

true

The set of solution points that satisfies all of a linear programming problem's constraints simultaneously is defined as the feasible region in graphical linear programming.

true

When looking at the arrivals at the ticket counter of a movie theater, we can assume an unlimited queue.

true