A condensed discussion on estimation for software, including the COCOMO model.

1. Estimation for Software

2. What is Estimation?
A rough calculation of the value, number, quantity
or something.
Software Estimation :
A set of predictable activities of
s/w project.

3. A good estimation is :
i. a prediction
ii. that provides a clear view
iii. of the project reality
iv. Make decisions to control the project
v. to reach its targets.
Knowing where you come from, where you are
and where you are going

4. An estimation does :
i. an analytical and unbiased prediction
ii. how long it takes
iii. what it will cost
The bias comes from the interplay with targets,
commitments and plans

5. Target :
- Desirable business objective
Estimate :
- Analytical prediction
- With an uncertainty range
Commitment :
- Promise to deliver
- Defined functionality and quality
Plan :
-Bridging the gap between estimation and
commitment.

6. Software Estimation attributes :
i. Project complexity
ii. Project size
iii. The degree of uncertainity
iv. Availability of info
v. Risk Estimation

7. Functions Features
Software Scope
Feasibility
Can we
meet
scope?

8. Resources
Human Reusable
Environm
ent
OFF the shelf
Full Experience Partial Experience
New

9. The software Equation :
E=LOC*(B^ 0.33)/(P^3*t^4)

10. Constructive Cost Estimation Model
Organic
Semidetached Embedded

11. Constructive Cost Estimation Model :
Modes :
Organic :
i. User friendly software
ii. Developers are fully experienced
iii. Familiar and stable environment
Semidetached :
i. User friendly software
ii. Between Organic and Embedded modes
iii. Developers are fully or half experienced
Embedded :
i. Hardware related software
ii. New project involving new inventions

12. Ideally an
estimate should
be produced by
using these ten-
step process

13. Cocomo Model
Basic Intermediate
Complete/
Detailed
Cocomo Model :
A procedural cost estimation model for software projects
Consider single System
Consider combination of subSystem

14. Basic COCOMO:
i. Gives approximate estimate of the various parameters of
the project
(Product Size/ LOC/ performance/ schedule/ cost).
Intermediate COCOMO:
EAF (Effort Adjustment Factor) is used from 15 cost
drivers that are based on different software development
attributes
Complete COCOMO:
Calculates the different Effort Multipliers are used for
each phase of project as the total of the estimates of all
the individual subsystems

15. Factors of Intermediate :
i. Product
ii. Computer
iii. Personnel
iv. Development Environment

16. Basic Subsystem of complete :
i. Database part
ii. Graphical user interface (GUI) part
iii. Communication

17. Lines of Code Based Estimation :
i. What is the LOC.?
ii. Why LOC is important in S/W ?
iii. Type of LOC..?
1. physical
2. logical

18. Function Points Based Estimation :
i. What is function point.?
ii. Type of function points?
1.input
2.output
3.inquiries
4.internal files
5.external files
iii. Why need function points?