# Cpm

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cpm scheduling

## Content

Example of COCOMO
Please use the COCOMO method to estimate the size (in terms of
line of code in C) and the effort (in terms of man month) of a
software project, which is described in the following table.
Measurement
Parameter
# of user input
# of user output
# of user inquires
# of files
# of external interfaces

Count

Weight Factor

10
15
8
25
6

3
4
3
7
5

or
or
or
or
or

4
5
4
10
7

Weight

or 6
or 7
or 6
or 15
or 10

Solution:
Step 1. Compute the UFC (unadjusted function-point) count
Measurement
Parameter
# of user input
# of user output
# of user inquires
# of files
# of external interfaces

Count

Weight Factor

10
15
8
25
6

3
4
3
7
5

or
or
or
or
or

4 or 6
5 or 7
4 or 6
10 or 15
7 or 10

Weight
60
75
48
375
42

UFC = 60 + 75 + 48 +375 + 42 = 600
Step 2. Compute the FC (function point) provided the project
complexity factor is 350
FP = UFC * (0.65 + 0.01 * 35) = 600 * (0.65 + 0.35) = 600

Step 3. Compute the code size in C, and its average lines of
code/FP is 128
Code Size = 128 * 600 = 76800
Step 4. Estimate the effort if the project’s complexity is moderate.
E = 3.0 * (76.8) ^1.12 = 3 * 129.3 = 388

Example of CPM
The software project consists of a list of tasks along with their
estimated durations which are shown in the estimation table below.
The project manager also knows the dependencies among those
tasks. Please make a CPM graph and a Gantt chart to show how to
organize all the tasks so that the project can be down in the shortest
time by Nancy and Julia.
A
B
C
D
E
F
G
H
I

Dependency

A
A
B and C
B and C
D and E
D and E
F and G

Duration
4
3
8
7
9
12
2
5
6

Solution:
Step 1. Draw the dependency graph

B

A

D

C

E

H

F

G

I

Step 2. Find the critical path

A
B
C
D
E
F
G
H
I

Dependency Duration
4
3
8
A
7
A
9
B and C
12
B and C
2
D and E
5
D and E
F and G
6

Earliest finish time
4
3
12
11
21
24
23
26
30

The critical path is A→C→F→I.
The earliest completion time is 4 + 8 + 12 + 6 = 30.

Step 3. Assign the tasks to Nancy and Julia, and compute the
earliest start time

Nancy

Julia

0

A

4

4

0

B
3

D

12

7

4

C
8

12

F
12

E
9

24

I
6

21 G
2

24 H
5

Step 4. Compute the latest possible start time given the earliest
completion time, 30.

Nancy

Julia

0

A

4

D

0

4

5

7

F
12 12

0

B

4

C

12

E

1

3

4

8

13

9

12

24

I

24

6

21 G
22 2

23 H
25 5

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#### Cpm

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