ºÝºÝߣ

ºÝºÝߣShare a Scribd company logo

Cocomo model

?Download as PPSX, PDF?
?
D
Devan Thakur

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. Basic COCOMO compute software development effort (and cost) as a function of program size. Program size is expressed in estimated thousands of source lines of code (SLOC, KLOC).

1 of 18
Downloaded 286 times
COCOMO MODEL Software Engineering Prepared By Devan Sharma
COCOMO Model COCOMO was first published in 1981 Barry W. Boehm's Book Software engineering economics Fig : 1 W.Boehm
COCOMO Model COCOMO model is used to estimate size ,cost and time of software to be developed Cost Size Time Fig 2: Need of COCOMO
COCOMO MODEL Types Type of software Semidetached Organic Embedded
COCOMO Mode Project size Nature of Project Organic Typically 2-50 KLOC Small size project, experienced developers in the familiar environment. For example, pay roll, inventory projects ,Banking system Semi detached Typically 50-300 KLOC Medium size project, Medium size team, Average previous experience on similar project. For example: Utility systems like compilers, database systems Embedded Typically over 300 KLOC Large project, Real time systems, Complex interfaces, Very little previous experience. For example: ATMs, Air Traffic Control ,Navigation satellite Table 1: The comparison of three COCOMO modes
Person-Month ? Person-month (PM) is considered to be an appropriate unit for measuring effort
COCOMO MODEL The Constructive Cost Model (COCOMO) Constructive Cost model (COCOMO) Basic Intermediate Complete(detailed) Model proposed by B. W. Boehm¡¯s through his book Software Engineering Economics in 1981
COCOMO MODEL Basic Model Basic COCOMO model takes the form E=ab(KLOC) PM bb db D=cb (E) where E is effort applied in Person-Months, and D is the development time in months. The coefficients ab, bb, cb and db are given in table Months
Fig 3: COCOMO Model equation
Effort versus product size. Fig 4 : Graph for effort
Development time versus size. Fig 4 : Graph for Time
Disadvantages of Basic COCOMO Model ? It considers only KLOC to estimate effort ? It can not be used for modern tools ? It does not consider different parameters Note : Intermediate COCOMO model considers different parameters to estimate effort and time
COCOMO MODEL Intermediate Model Cost drivers (i) Product Attributes Required s/w reliability (accuracy) Size of application database Complexity of the product (ii) Hardware Attributes Run time performance constraints Memory constraints Speed of system
COCOMO MODEL (iii) Personal Attributes Analyst capability Programmer capability Application experience Virtual m/c experience Programming language experience (iv) Project Attributes Modern programming practices Use of software tools
COCOMO model Disadvantage of basic and intermediate COCOMO model ? A major shortcoming of both the basic and the intermediate COCOMO models is that they consider a software product as a single homogeneous entity. ? Now these days large software systems are made up of several smaller sub-systems or modules with different characteristics.
Complete COCOMO model ? The complete COCOMO model considers different subsystems of the software ? For example CU website has different modules or subsystem ? Graphical user interface (Front End) ? Database (your data is stored )
Complete COCOMO model ? Different modules or subsystems of the complete COCOMO model ?Database part ? Graphical user interface (GUI) part ? Communication part ? Communication part can be considered as embedded software. ? The database part could be semi-detached software ? The GUI part organic software. The costs for these three components can be estimated separately, and summed up to give the overall cost of the system
Cocomo model

More Related Content

Cocomo model

  • 2. COCOMO Model COCOMO was first published in 1981 Barry W. Boehm's Book Software engineering economics Fig : 1 W.Boehm
  • 3. COCOMO Model COCOMO model is used to estimate size ,cost and time of software to be developed Cost Size Time Fig 2: Need of COCOMO
  • 4. COCOMO MODEL Types Type of software Semidetached Organic Embedded
  • 5. COCOMO Mode Project size Nature of Project Organic Typically 2-50 KLOC Small size project, experienced developers in the familiar environment. For example, pay roll, inventory projects ,Banking system Semi detached Typically 50-300 KLOC Medium size project, Medium size team, Average previous experience on similar project. For example: Utility systems like compilers, database systems Embedded Typically over 300 KLOC Large project, Real time systems, Complex interfaces, Very little previous experience. For example: ATMs, Air Traffic Control ,Navigation satellite Table 1: The comparison of three COCOMO modes
  • 6. Person-Month ? Person-month (PM) is considered to be an appropriate unit for measuring effort
  • 7. COCOMO MODEL The Constructive Cost Model (COCOMO) Constructive Cost model (COCOMO) Basic Intermediate Complete(detailed) Model proposed by B. W. Boehm¡¯s through his book Software Engineering Economics in 1981
  • 8. COCOMO MODEL Basic Model Basic COCOMO model takes the form E=ab(KLOC) PM bb db D=cb (E) where E is effort applied in Person-Months, and D is the development time in months. The coefficients ab, bb, cb and db are given in table Months
  • 9. Fig 3: COCOMO Model equation
  • 10. Effort versus product size. Fig 4 : Graph for effort
  • 11. Development time versus size. Fig 4 : Graph for Time
  • 12. Disadvantages of Basic COCOMO Model ? It considers only KLOC to estimate effort ? It can not be used for modern tools ? It does not consider different parameters Note : Intermediate COCOMO model considers different parameters to estimate effort and time
  • 13. COCOMO MODEL Intermediate Model Cost drivers (i) Product Attributes Required s/w reliability (accuracy) Size of application database Complexity of the product (ii) Hardware Attributes Run time performance constraints Memory constraints Speed of system
  • 14. COCOMO MODEL (iii) Personal Attributes Analyst capability Programmer capability Application experience Virtual m/c experience Programming language experience (iv) Project Attributes Modern programming practices Use of software tools
  • 15. COCOMO model Disadvantage of basic and intermediate COCOMO model ? A major shortcoming of both the basic and the intermediate COCOMO models is that they consider a software product as a single homogeneous entity. ? Now these days large software systems are made up of several smaller sub-systems or modules with different characteristics.
  • 16. Complete COCOMO model ? The complete COCOMO model considers different subsystems of the software ? For example CU website has different modules or subsystem ? Graphical user interface (Front End) ? Database (your data is stored )
  • 17. Complete COCOMO model ? Different modules or subsystems of the complete COCOMO model ?Database part ? Graphical user interface (GUI) part ? Communication part ? Communication part can be considered as embedded software. ? The database part could be semi-detached software ? The GUI part organic software. The costs for these three components can be estimated separately, and summed up to give the overall cost of the system