Project Management

Definition

Network planning technique

Project -- a series of related jobs direct towards some major output and require a significant amount of time to perform

Project Management -- plan, direct, and control resources to meet the technical, cost, and time constraints of the project

Network planning models

1.  Define the project, i.e., all activities
2.  Determine the sequence and relationships of the activities
3.  Assign time estimates to each activity (CPM: activity times are known vs. PERT: 3 time estimates for each activity)
4.  Develop a network diagram
5.  Compute the longest time path through the network (Critical Path Analysis)
6.  Use the network to plan, schedule, monitor, and control the project

An example
 
Activity
Immediate Predecessor
A
-
B
-
C
A
D
B
E
C
F
C
G
D,E
H
F,G


 

 

CPM -- single time estimate for each activity
 
Activity
Time
A
2
B
3
C
2
D
4
E
4
F
3
G
5
H
2

PERT -- 3 time estimates for each activity:

Optimistic time: a

Most likely time: m

Pessimistic time: b


 
Activity
Optimistic Time
Most Likely Time
Pessimistic Time
Expected Time
A
1
2
3
2
B
2
3
4
3
C
1
2
3
2
D
2
4
6
4
E
1
4
7
4
F
1
2
9
3
G
3
4
11
5
H
1
2
3
2

Critical path analysis (CPA)

Earliest start time (ES) = max (EF of predecessors)

Latest start time (LS)

Earliest finish time (EF)

Latest finish time (LF) = min (LS of successors)

Slack = LS - ES or LF - EF

Critical path: activities that have zero slack
 
Activity
ES
EF
LS
LF
Slack
Critical
A
0
2
0
2
0
Yes
B
0
3
1
4
1
C
2
4
2
4
0
Yes
D
3
7
4
8
1
E
4
8
4
8
0
Yes
F
4
7
10
13
6
G
8
13
8
13
0
Yes
H
13
15
13
15
0
Yes

Total project completion time = sum of times of activities on the critical path

Pg. 81 problems 5, 6

Exercises

Pg.81 Problems 2, 3, 7, 9