Code for Cost Estimation by COCOMO Model

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ASSIGNMENT II PROBLEM STATEMENT: Design a procedure to determine the Effort, Time and number of Personal required for developing software for an Organic Type using COCOMO. The values of the effective customer drivers are to be read from an array and the number of Lines Of Code (LOC) would be supplied as data.CONSTRUCTIVE COST MODEL (COCOMO) The Constructive Cost Model (COCOMO) is an algorithmic software cost estimation model developed by Barry Boehm. The model uses a basic regression formula,

Transcript

ASSIGNMENT II PROBLEM STATEMENT: Design a procedure to determine the Effort, Time and number of Personal required for developing software for an Organic Type using COCOMO. The values of the effective customer drivers are to be read from an array and the number of Lines Of Code (LOC) would be supplied as data.

CONSTRUCTIVE COST MODEL (COCOMO) The Constructive Cost Model (COCOMO) is an algorithmic software cost estimation model developed by Barry Boehm. The model uses a basic regression formula, with parameters that are derived from historical project data and current project characteristics. COCOMO consists of a hierarchy of three increasingly detailed and accurate forms. The first level, Basic COCOMO is good for quick, early, rough order of magnitude estimates of software costs, but its accuracy is limited due to its lack of factors to account for difference in project attributes (Cost Drivers). Intermediate COCOMO takes these Cost Drivers into account and Detailed COCOMO additionally accounts for the influence of individual project phases. Basic COCOMO Basic COCOMO computes software development effort (and cost) as a function of program size. Program size is expressed in estimated thousands of lines of code (KLOC) COCOMO applies to three classes of software projects:

Organic projects - "small" teams with "good" experience working with "less than rigid" requirements Semi-detached projects - "medium" teams with mixed experience working with a mix of rigid and less than rigid requirements Embedded projects - developed within a set of "tight" constraints (hardware, software, operational, ......)

The basic COCOMO equations take the form Effort Applied = ab(KLOC)bb [ person-months ] Development Time = cb(Effort Applied)db [months] People required = Effort Applied / Development Time [count]

The coefficients ab, bb, cb and db are given in the following table. Software project ab Organic 2.4 Semi-detached 3.0 Embedded 3.6 bb 1.05 1.12 1.20 cb db 2.5 0.38 2.5 0.35 2.5 0.32

Basic COCOMO is good for quick estimate of software costs. However it does not account for differences in hardware constraints, personnel quality and experience, use of modern tools and techniques, and so on. Intermediate COCOMOs Intermediate COCOMO computes software development effort as function of program size and a set of "cost drivers" that include subjective assessment of product, hardware, personnel and project attributes. This extension considers a set of four "cost drivers",each with a number of subsidiary attributes:

Product attributes o Required software reliability o Size of application database o Complexity of the product Hardware attributes o Run-time performance constraints o Memory constraints o Volatility of the virtual machine environment o Required turnabout time Personnel attributes o Analyst capability o Software engineering capability o Applications experience o Virtual machine experience o Programming language experience Project attributes o Use of software tools o Application of software engineering methods o Required development schedule

Each of the 15 attributes receives a rating on a six-point scale that ranges from "very low" to "extra high" (in importance or value). An effort multiplier from the table below applies to the rating. The product of all effort multipliers results in an effort adjustment factor (EAF). Typical values for EAF range from 0.9 to 1.4.

Cost Drivers Product attributes Required software reliability Size of application database Complexity of the product Hardware attributes Run-time performance constraints Memory constraints Volatility of the virtual machine environment Required turnabout time Personnel attributes Analyst capability Applications experience Software engineer capability Virtual machine experience Programming language experience Project attributes Application of software engineering methods Use of software tools Required development schedule

Ratings Very Very Extra Low Low Nominal High High High 0.75 0.88 0.94 0.70 0.85 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.15 1.40 1.08 1.16 1.15 1.30 1.65 1.11 1.06 1.15 1.07 1.30 1.66 1.21 1.56 1.30 1.15

0.87 0.87 1.46 1.29 1.42 1.21 1.14 1.19 1.13 1.17 1.10 1.07

0.86 0.71 0.91 0.82 0.86 0.70 0.90 0.95 0.91 0.82 0.91 0.83 1.04 1.10

1.24 1.10 1.24 1.10 1.23 1.08

The Intermediate Cocomo formula now takes the form: E=ai(KLoC)(bi).EAFwhere E is the effort applied in person-months, KLoC is the estimated number of thousands of delivered lines of code for the project, and EAF is the factor calculated above. The coefficient ai and the exponent bi are given in the next table. Software project Organic Semi-detached Embedded PROGRAM CODE:. // Effort, Time and number of Personal determination #include #include #include #include ai 3.2 3.0 2.8 bi 1.05 1.12 1.20

main() { int i,ch; double kloc,iee,eaf,aee,dt,pi; //double approx_aee,approx_dt,approx_pi; //double fraction,integer; struct cost_drivers { char a[30]; double r[6]; }; struct cost_drivers drivers[] = { {"RELY",.75,.88,1,1.15,1.4,0}, {"DATA",0,.94,1,1.08,1.16,0}, {"CPLX",.7,.85,1,1.15,1.3,1.65}, {"TIME",0,0,1,1.11,1.30,1.66}, {"STOR",0,0,1,1.06,1.21,1.56}, {"VITR",0,.87,1,1.15,1.3,0}, {"TURN",0,.87,1,1.07,1.15,0}, {"ACAP",1.46,1.19,1,.86,.71,0}, {"AEXP",1.29,1.13,1,.91,.82,0}, {"PCAP",1.42,1.17,1,.86,.7,0}, {"VEXP",1.21,1.1,1,.9,0,0}, {"LEXP",1.14,1.07,1,.95,0,0}, {"MODP",1.24,1.1,1,.91,.82,0}, {"TOOL",1.24,1.1,1,.91,.83,0}, {"SCHED",1.23,1.08,1,1.04,1.1,0} }; printf("ENTER THE NO. OF LINES OF SOURCE CODE (in kloc) : "); scanf("%lf",&kloc); iee = 3.2 * (pow(kloc,1.05)); sprintf("\nENTER THE RATING OF EACH COST DRIVERS : \n\n"); eaf = 1; for (i=0;i0 && ch>=0 && ch

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