Assignment:
You and several friends are about to prepare a lasagna dinner. The tasks to be performed, their immediate predecessors, and their estimated durations are as follows:
|
Task
|
Task Description
|
Tasks that
Must Precede
|
Time
|
|
A
|
Buy the mozzarella cheese•
|
|
30 minutes
|
|
B
|
Slice the mozzarella
|
A
|
5 minutes
|
|
C
|
Beat 2 eggs
|
|
2 minutes
|
|
D
|
Mix eggs and ricotta cheese
|
C
|
3 minutes
|
|
E
|
Cut up onions and mushrooms
|
|
7 minutes
|
|
F
|
Cook the tomato sauce
|
E
|
25 minutes
|
|
G
|
Boil large quantity of water
|
|
15 minutes
|
|
H
|
Boil the lasagna noodles
|
G
|
10 minutes
|
|
I
|
Drain the lasagna noodles
|
H
|
2 minutes
|
|
1
|
Assemble all the ingredients
|
I, F, D, B
|
10 minutes
|
|
K
|
Preheat the oven
|
|
15 minutes
|
|
L
|
Bake the lasagna
|
AK
|
30 minutes
|
"There is none in the refrigerator.
(a) Construct the project network for preparing this dinner.
(b) Find all the paths and path lengths through this project network. Which these paths is critical path?
(c) Find the earliest start time and earliest finish time for each activity
(d) Find the latest start time and latest finish time for each activity.
(e) Find the slack for each activity. Which of the paths is a critical path?
(f) Because of a phone call, you were interrupted for 6 minutes when you should have been cutting the onions and mushrooms. By how much will the dinner bedelayed? If you use your food processor, which reduces the cutting time from 7 to 2 minutes, will the dinner still be delayed?