Constructive Cost Model (COCOMO)

          The Constructive Cost Model (COCOMO) is an algorithmic software cost estimation model developed by Barry Boehm. Every Final year project Black book inevitably requires a Cocomo model as per their project. I see many students searching for cocomo model but not getting the right thing required by the Examiner, Today I bring you a cocomo model which i did used my self for my project and you too can use it for yours just make sure you customized it according to your needs...  

Cost Analysis

         For a given set of requirements it is desirable to know how much it will cost to develop the software to satisfy the given requirements, and how much time development will take. These estimates are needed before development is initiated. The primary reason for cost and schedule estimation is to enable the client or developer to perform a cost-benefit analysis and for project monitoring and control. Cost in a project is due to the requirements for software, hardware and human resources. Most cost estimates are determined in terms of Person month (PM).

We have used COCOMO (Constructive Cost Model). The Intermediate COCOMO model computes software development effort as a function of program size and a set of "cost drivers" that include subjective assessments of product, hardware, personnel and project attributes. This model estimates the total effort in terms of person-months of the technical project staff. The important steps in this analysis are:

v Obtain an initial estimate of the development effort from the estimate of thousand of delivered lines of source code (KLoC)

      The initial estimate (also called as nominal estimate) is determined by an equation of the form used in the static single-variable models, using KLoC as the measure of size.

      To determine the initial effort Ei in person- months the equation used is,

Ei = a * (KLoC) b

      Where, a and b are constants which are determined depending on the type of the project. Since, this project is of Windows based type, therefore the values of a = 1.40 and the value of b = 0.6 and KLoC is the number of lines of source code which is .874 KLoC. Thus the value of E_i is:

E_i = 1.40 * (0.874) * 0.60 = 0.73416 PM

v Determine a set of 15 multiplying factors from different attributes of the product which are:

Table: Cost Estimation Table

Cost Drivers	Very low	Low	Normal	High	Very High
Product Attribute
RELY, required reliability	0.75	0.88	1.00	1.15	1.40
DATA, database size		0.94	1.00	1.08	1.16
CPLX, product complexity	0.70	0.85	1.00	1.15	1.30
Computer Attribute
TIME, execution time constraint			1.00	1.11	1.30
STOR, main storage constraint			1.00	1.06	1.21
VITR, virtual machine volatility		0.87	1.00	1.15	1.30
TURN, computer turnaround time		0.87	1.00	1.07	1.15
Personnel Attribute
ACAP, analyst capability	1.46	1.19	1.00	0.86	0.71
AEXP, application experience	1.29	1.13	1.00	0.91	0.82
PCAP, programmer capability	1.42	1.17	1.00	0.86	0.70
VEXP, virtual machine experience	1.21	1.10	1.00	0.90
LEXP, programming language experience	1.14	1.07	1.00	0.95
Project Attributes
MODP, modern programming practices	1.24	1.10	1.00	0.91	0.82
TOOL, use of SW tools	1.24	1.10	1.00	0.91	0.83
SCHED, development schedule	1.23	1.08	1.00	1.04	1.10

v Adjust the effort estimate by multiplying the initial estimate with the entire multiplying factor.

We have taken the factors:

ü  Reliability

ü  Complexity

ü  Time Constraints

ü  Turnaround time

ü  Analyst capability

ü  Programmer capability

ü  Programming language experience

ü  Modern Programming practices

ü  Use of SW tools

ü  Development Schedule

Based on these factors we have calculated, Effort Adjustment Factor (EAF) as follows:

EAF = 1.15 *  0.85 * 1.00  *  0.87  *  1.00  *  1.00  *  1.07  *  1.10  *  0.91 * 1.00

        = 0.91087

The final effort estimate, E is determined by multiplying the initial estimate by the EAF:

         E=EAF * E_i

           = 0.91087 * 0.73416

           = 0.6687 Person Month

 We take the assumption charges are 40 rupees per day.

Total estimation = 191 * 0.6687 * 40

                                                 =  5100 Rupees.