Project Management Questions-
Q1. Consider the following project activities
|
Activity
|
Duration (Days)
|
Immediate Predecessors
|
|
A
|
4
|
None
|
|
B
|
3
|
A
|
|
C
|
7
|
A
|
|
D
|
9
|
A
|
|
E
|
8
|
A
|
|
F
|
7
|
B
|
|
G
|
6
|
C
|
|
H
|
13
|
C
|
|
I
|
4
|
D, E
|
|
J
|
12
|
E
|
|
K
|
1
|
E
|
|
L
|
5
|
F, G,H
|
|
M
|
4
|
I, J, K
|
|
N
|
5
|
L, M
|
a. Draw the network diagram.
b. Show the early start, early finish, late start, and late finish times.
c. Show the critical path.
d. Suppose you have the option of shorting any or all of C, D, H and J each one day, which would you shorten?
e. What is the new critical path and earliest completion time?
Q2. Oxford RV is planning to launch a new model of RVs. The project activities are as follows:
|
ACTIVITY
|
|
Immediate Predecessors
|
Required Time (Weeks)
|
Cost
|
|
Normal
|
Crash
|
Normal
|
Crash
|
|
A
|
Hiring workers
|
None
|
8
|
5
|
$4,000
|
$10,000
|
|
B
|
Install equipment
|
None
|
6
|
5
|
$7,000
|
$11,000
|
|
C
|
Order materials
|
None
|
3
|
2
|
$20,000
|
$21,000
|
|
D
|
Test equipment
|
B
|
4
|
2
|
$5,000
|
$10,000
|
|
E
|
Train workers
|
A,B
|
6
|
4
|
$8,000
|
$18,000
|
|
F
|
Run pilot tests
|
C,D
|
5
|
2
|
$25,000
|
$34,000
|
1. What are the critical path and the estimated completion time?
2. To shorten the project by two weeks, which tasks would be shortened and what would the final total project cost be?
Process and Little's Law
Q3. Patients at Hoosiers Dental complained that the waiting time was too long and the dentist has asked you to investigate the problem. Based on conversation with staff members at the clinic, you have collected the information about the process. The service process includes four activities that are conducted in the sequence described below (the time required for each activity is shown in parentheses):
- Activity 1: Fill out the paperwork (5 mins)
- Activity 2: Enter patient information into the system (5 mins)
- Activity 3: Take an X-ray (15 mins)
- Activity 4: dental checkup (30 mins)
a. Which activity is the bottleneck?
b. What is the capacity of the entire process?
c. Assuming unlimited demand, what is the flow rate of the entire process?
d. What is the utilization rate of the employee at activity 3?
Q4. AutoDesk has 30 employees who work at its online customer service chat room. It receives, on average, 240 request per hour and each session takes 5 minutes to complete. On average, how many chat sessions are active?
Break-even analysis
Q5. Pat Egan owns a firework store. The store's fixed costs are $24,000 a month, and each firework assortment costs about $8, on average. The average selling price for an assortment is $20.
a. What is the break-even point for Pat's firework store?
Suppose Pat decides to expand his business. After expansion, the new fixed expense will be $40,000 per month, but the average cost for an assortment will be reduced to $5 due to his larger purchase volume.
b. What is the new break-even point?
c. At what volume point is Pat indifferent to the two alternatives outlined above?
Service Process
Q6. A car wash has a single crew of workers. Cars arrive the car wash every 8 minutes, following a Poisson distribution. The car wash can wash one car every 6 minutes and service times are exponentially distributed. Based on these numbers, find the following:
a. The average number of cars waiting.
b. The average number of cars in the system.
c. The average time a car spends waiting.
d. The average time a car spends in the system.