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
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.
Tasks
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
Tasks
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.