1. LOC, COCOMO I & COCOMO II
Subject: Software Engineering Coordinator: Mr Anoj Kumar
Presented By:
Kamal Kishore (2012ca34)
Jyoti Shrivastava (2012ca52)
Kalyan Mondal (2012ca49)
Jyotsna Agnihotri (2012ca66)
Karishma Gupta(2012ca55)

2. Contents Software Planning LOC: Lines of Code Function Point
Cost Estimation
Development Mode
COCOMO I
Basic COCOMO
Intermediate COCOMO
Detailed COCOMO
COCOMO II
Application Composition
Early Design Model
Post Architecture Model
References

3. SOFTWARE PLANNING
Software planning begins before technical work starts, continues as the software
Evolves from concept to reality, and culminates only when the software is retired.
Fig:- Activities during software project planning
Created by:- Kamal kishore(2012ca34)
Ref :-software engineering by K.K.Agrawal, yogesh singh

4. LINES OF CODE(LOC)
A Line of code is any line of program text that is not a comment or blank line, regardless of the number of statements or fragments on the line. This specifically includes all lines containing program header, declarations, and executable and non-executable statements.
While line of codes have their uses, their usefulness is limited for other tasks like functionality, complexity, efficiency, etc.
Created by:- Kamal kishore(2012ca34)
Ref :-software engineering by K.K.Agrawal, yogesh singh

5. Internal Logical Files External Interface Files
FUNCTION POINT
Function point measures functionality which is a solution to the size measurement problem.
It is decomposed into following functional units
Inputs
Outputs
Enquiries
Internal Logical Files
External Interface Files
Created by:- Kamal kishore(2012ca34)
Ref :-software engineering by K.K.Agrawal, yogesh singh

6. FUNCTIONAL UNITS WITH WEIGHTING FACTORS
Low
Average
High
External Inputs 3 4 6
External Outputs 5 7
External Inquiries
Internal logical files (ILF) 10 15
External interface files (EIF)
The procedure for the calculation of UFP in mathematical form is given below
UFP = ∑ ∑ 𝑍 𝑖𝑗 WijUFP : Unadjusted Function Point i=1 j=1
Where i indicates the row and j indicates the column of table.
Wij : It is the entry of ith row and jth column of the table.
Zij: It is the count of the number of functional unit of type i that have been classified as having the complexity corresponding to column j
Created by:- Kamal kishore(2012ca34)
Ref :-software engineering by K.K.Agrawal, yogesh singh

7. An example
Consider a project with the following functional units: 50 user inputs,40 user outputs, 35 user enquiries,6 user files,4 external interfaces.
Assume all complexity adjustment factors and weighting factors are average.
Compute the function points for the project. Suppose that program needs 70 LOC per FP. Find out the size of complete project.
Solution:
UFP = ∑ ∑ 𝑍 𝑖𝑗 Wij
i=1 j=1
UFP= 50 * * * * * 7
= = 628
CAF= ( ∑ 𝐹 𝑖 )
=( (14 * 3 )) = 1.07
FP= UFP * CAF
=628 * 1.07 = 672
Size = FP * (LOC per FP) = 672 * 70 = LOC
Created by:- Kamal kishore(2012ca34)
Ref :-software engineering by K.K.Agrawal, Yogesh Singh

8. Cost Estimation
Approximate judgement of the costs for a project. It should be done throughout the entire life cycle.
Why we need?
To determine how much effort and time a software project requires.
Important for making good management decisions.
It facilitates competitive contract bids.
It affect the planning and budgeting of a project.
Ref: Software Engineering By K.K.Aggarwal & Y. Singh Created by: Jyoti Shrivastava

9. Development Mode of S/W Projects
Size
Nature of Project
Innovation
Deadline
Organic
Typically
2-50 KLOC
Small size project, Experienced developers.
Little
Not Tight
Semi Detached
50-300KLOC
Medium size project and team.
Medium
Embedded
Typically over 300KLOC
Large project, Real-time systems
Significant
Tight

10. Constructive Cost Model(COCOMO )
The COCOMO model is a single variable software cost estimation model developed by Barry Boehm in
The model uses a basic regression formula, with parameters that are derived from historical project data and current project characteristics.
Hierarchy of Cocomo Model
Basic COCOMO model
Intermediate COCOMO model
Detailed COCOMO model
Ref: Software Engineering By K.K.Aggarwal & Y. Singh Created by: Jyoti Shrivastava

11. Basic COCOMO Model It take the form:
Effort(E) = ab * (KLOC)bb(in Person-months)
DevelopmentTime(D) = cb * (E) db (in month)
Average staff size(SS) = E/D (in Person)
Productivity(P) = KLOC / E (in KLOC/Person-month)
Project ab bb cb db
Organic
2.4
1.05
2.5
0.38
Semidetached
3.0
1.12
0.35
Embedded
3.6
1.20
0.32
Ref: Software Engineering By K.K.Aggarwal & Y. Singh Created by: Jyoti Shrivastava

12. What is Person-Months ? The area under the curve
Ref: Fundamentals of Software Engineering By Rajib Mall Created by: Jyoti Shrivastava

13. Basic cocomo: Example
A project size of 200KLOC is to be developed.S/W development team has average experience on similar type of projects.The project schedule is not very tight.Calculate the effort and development time of the project.
Ans: KLOC implies semi-detached mode.
Hence, E= 3.0 * (200)1.12 = PM
D=2.5 * ( )0.35 = 29.3 M
Avg. staff size(SS) = E/D
= /29.3=38.67 Persons.
Productivity (P) = KLOC/E
= 200/ = KLOC/PM.
Ref: Software Engineering By K.K.Aggarwal & Y. Singh Created by: Jyoti Shrivastava

14. Intermediate COCOMO Extension of Basic COCOMO Why Use ?
Basic model lacks accuracy
Computes software development effort as a function of program size and set of 15 Cost Drivers
Cost Driver: A multiplicative factor that determines the effort required to complete the software project.
Why Cost Drivers?
Adjust the nominal cost of a project to the actual project Environment.
For each Characteristics, Estimator decides the scale factor
Ref: Software Engineering By K.K.Aggarwal & Y. Singh Created by: Kalyan Mondal
Very Low
Low
Nominal
High
Very High
Extra High

15. Cost Drivers Required Software Reliability (RELY) Database Size (DATA)
Product Attributes
Required Software Reliability (RELY)
Database Size (DATA)
Product Complexity (CPLX)
Computer Attributes
Execution Time Constraint (TIME)
Main Storage constraint (STOR)
Virtual Machine volatility (VIRT)
Computer turnaround time (TURN)
Personnel Attributes
Analyst Capability (ACAP)
Application Experience (AEXP)
Programmer Capability (PCAP)
Virtual Machine Experience (VEXP)
Programming language Experience (LEXP)
Project Attributes
Modern programming practices (MODP)
Use of Software tools (TOOL)
Required development schedule (SCED)
Ref: Software Engineering By K.K.Aggarwal & Y. Singh Created by: Kalyan Mondal

16. The Calculation Project ab bb cb db
Multiply all 15 Cost Drivers to get Effort Adjustment Factor(EAF)
E(Effort) = ab(KLOC)bb * EAF(in Person-Month)
D(Development Time) = cb(E)db (in month)
SS (Avg Staff Size) = E/D (in persons)
P (Productivity) = KLOC/E (in KLOC/Person-month)
Project ab bb cb db
Organic
3.2
1.05
2.5
0.38
Semidetached
3.0
1.12
0.35
Embedded
2.8
1.20
0.32
Ref: Software Engineering By K.K.Aggarwal & Y. Singh Created by: Kalyan Mondal

17. Intermediate COCOMO : Example
A new project with estimated 400 KLOC embedded system has to be developed. Project manager hires developers of low quality but a lot of experience in programming language. Calculate the Effort, Development time, Staff size & Productivity. EAF = 1.29 * 0.95 = LOC implies Embedded System Effort = 2.8*(400)1.20 * = 3712 * 1.22 = 4528 person-months Development Time = 2.5 * (4528)0.32 = 2.5 * = 36.9 months Avg. Staff Size = E/D = 4528/36.9 = 122 persons Productivity = KLOC/Effort = 400/4528 = KLOC/person-month
Cost Drivers
Very Low
Low
Nominal
High
Very High
Extra High
AEXP
1.29
1.13
1.00
0.91
0.82 --
LEXP
1.14
1.07
0.95
Ref: Software Engineering By K.K.Aggarwal & Y. Singh Created by: Kalyan Mondal

18. Detailed COCOMO
Detailed COCOMO = Intermediate COCOMO assessment of Cost Drivers impact on each phase.
Phases
Plans and requirements
System Design
Detailed Design
Module code and test
Integrate and test
Cost of each subsystem is estimated separately. This reduces the margin of error.
Ref: Software Engineering By K.K.Aggarwal & Y. Singh Created by: Kalyan Mondal

19. The Calculation
Multiply all 15 Cost Drivers to get Effort Adjustment Factor(EAF)
E(Effort) = ab(KLOC)bb * EAF(in Person-Month)
D(Development Time) = cb(E)db (in month)
Ep (Total Effort) = µp * E (in Person-Month)
Dp (Total Development Time) = τp * D (in month)
Ref: Software Engineering By K.K.Aggarwal & Y. Singh Created by: Kalyan Mondal

20. Detailed COCOMO : Example
Consider a project to develop a full screen editor. The major components identified and their sizes are (i) Screen Edit – 4K (ii) Command Lang Interpreter – 2K (iii) File Input and Output – 1K (iv) Cursor movement – 2K (v) Screen Movement – 3K. Assume the Required software reliability is high, product complexity is high, analyst capability is high & programming language experience is low. Use COCOMO model to estimate cost and time for different phases.
Size of modules : = 13 KLOC [Organic]
EAF = 1.15 * 1.15 * 0.86 * 1.07 =
Cost Drivers
Very Low
Low
Nominal
High
Very High
Extra High
RELY
0.75
0.88
1.00
1.15
1.40 --
CPLX
0.70
0.85
1.30
1.65
ACAP
1.46
1.19
0.86
0.71
LEXP
1.14
1.07
0.95
Ref: Software Engineering By K.K.Aggarwal & Y. Singh Created by: Kalyan Mondal

21. Example (Contd.)
Initial Effort (E) = ab(KLOC)bb * EAF = 3.2*(12)1.05 * = 52.9 person-months Initial Development Time = cb(E)db =2.5*(52.9)0.38 = months Phase value of µp and τp Phase wise effort & development time distribution
Plan & Reqr
System Design
Detail Design
Module code & test
Integration & Test
Organic Small µp
0.06
0.16
0.26
0.42
Organic Small τp
0.10
0.19
0.24
0.39
0.18 E D
Ep (in person-months)
Dp (in months)
Plan & Requirement
52.9
11.29
0.06*52.9 = 3.17
0.10*11.29=1.12
System Design
0.16*52.9=8.46
0.19*11.29=2.14
Detail Design
0.26*52.9=13.74
0.24*11.29=2.70
Module code & test
0.42*52.9=22.21
0.39*11.29=4.40
Integration & test
0.18*11.29=2.03
Ref: Software Engineering By K.K.Aggarwal & Y. Singh Created by: Kalyan Mondal

22. WHY COCOMO-II ?
 The changes in s/w development techniques included a move away from mainframe overnight batch processing to desktop- based real-time turnaround.
These changes and others began to make applying the original COCOMO model problematic.
The model is tuned to the life cycle practices of the 21st century.
Ref: Software Engineering By K.K.Aggarwal & Y. Singh and csse website by : Jyotsna Agnihotri

23. Categories Identified By Cocomo II
End User Programming
Infrastructure Sector
Intermediate Sectors
Application Generators And Composition Aids
Application Composition Sector
System Integration
Stages Of Cocomo-II
Application Composition
Earlier Design
Post Architecture
Ref: Software Engineering By K.K.Aggarwal & Y. Singh by : Jyotsna Agnihotri

24. Application Composition
Assess Object Counts
Classification Of Complexity Levels
Assign Complexity Weight To Each Object
Determine Object Points
Compute New Object Points
Calculation Of Productivity Rate
Compute The Effort In Person Months.

25. Classification of complexity levels:
Assess object counts: Estimate the number of screens, reports and 3 GL components that will comprise this application.
Classification of complexity levels:
We have to classify each object instance (depending on values of its characteristics) into :-
simple
medium
Difficult
Assign complexity weight to each object : The weights are used for three object types :-
screen
report
3GL components
Ref: Software Engineering By K.K.Aggarwal & Y. Singh by : Jyotsna Agnihotri

26. Object Points * (100 - %reuse)
Determine object points: Add all the weighted object instances to get one number and this known as object-point count.
Compute new object points: We have to estimate the percentage of reuse to be achieved in a project. Depending on the percentage reuse, the new object points (NOP) are computed.
Object Points * (100 - %reuse)
NOP =
100
NOP are the object points that will need to be developed and differ from the object point count because there may be reuse( percentage of the Product development which is accomplished by exploiting the existence of existing component's design-or-development effort).
Ref: Software Engineering By K.K.Aggarwal & Y. Singh&gilb.com by : Jyotsna Agnihotri

27. Productivity rate (PROD) = NOP/Person month
Calculation of productivity rate: The productivity rate can be calculated as:
Productivity rate (PROD) = NOP/Person month
Compute the effort in Persons-Months: When PROD is known, we may estimate effort in Person- Months as:
NOP
Effort in PM =
PROD
Ref: Software Engineering By K.K.Aggarwal & Y. Singh by : Jyotsna Agnihotri

28. Example
Example: Consider a database application project with the following characteristics:
The application has 4 screens with 4 views each and 7 data tables for 3 servers and 4 clients.
The application may generate two report of 6 sections each from 07 data tables for two server and 3 clients. There is 10% reuse of object points.
The developer’s experience and capability in the similar environment is low. The maturity of organization in terms of capability is also low. Calculate the object point count, New object points and effort to develop such a project.
Ref: Software Engineering By K.K.Aggarwal & Y. Singh by : Jyotsna Agnihotri

29. Solution : Lets have a look on the tables for screens, for reports , for complexity weights for each level
No. Of Views
Contained in a screen
Total<4
(<2 servers
<3 clients)
Total<8
(2-3 servers
3-5 clients)
Total 8+
(>3 servers
>5 clients)
<3
Simple
Medium
3-7
Difficult
>8
No. Of Sections
Contained in a report
Total<4
(<2 servers
<3 clients)
Total<8
(2-3 servers
3-5 clients)
Total 8+
(>3 servers
>5 clients)
0 or 1
Simple
Medium
2 or 3
Difficult 4+

30. Object Type Simple Complexity Medium Complexity Difficult Complexity
This project comes under the category of application composition estimation model.
Number of screens = 4 with 4 views each
Number of reports = 2 with 6 sections each
From Table we know that each screen will be of medium complexity and each report will be difficult complexity.
Using Table of complexity weights, we may calculate object point count
= 4 x x 8 = 24
Object Type
Simple Complexity
Medium
Complexity
Difficult Complexity
Screen 1 2 3
Report 5 8
3GL - 10
Ref: Software Engineering By K.K.Aggarwal & Y. Singh by : Jyotsna Agnihotri

31. Using the formula NOP is calculated as: NOP= 24 * (100-10)/100=21.6
Low value of productivity is given in above Productivity table = 7
Efforts in PM=NOP/PROD=21.6/7=3.086 PM
Developer’s Experience And Capability
PROD (NOP/PM)
Very low 4
Low 7
Nominal 13
High 25
Very high 50
Ref: Software Engineering By K.K.Aggarwal & Y. Singh by : Jyotsna Agnihotri

32. Early Design Model
Used in the early stages of a software project when very little may be known about:
the size of the product to be developed,
the nature of the target platform,
the nature of the personnel to be involved in the project.
Uses Unadjusted Function Points (UFP) as the measure of size.
Based on a standard formula for COCOMO-II models:
Where
PMnominal = Effort of the project in person months
A = Constant representing the nominal productivity, provisionally set to 2.5
B = Scale factor
Size = Software size
Created by- Karishma Gupta (2012CA55) Ref: Software Engineering By K.K. Aggarwal & Yogesh Singh

33. Early design cost drivers
The Scaling Factors that COCOMO-II model uses for the calculation of B are:
Precedentness (PREC)
Development flexibility (FLEX)
Architecture/ Risk Resolution (RESL)
Team Cohesion (TEAM)
Process maturity (PMAT)
Early design cost drivers
There are 7 early design cost drivers and are given below:
Product Reliability and Complexity (RCPX)
Required Reuse (RUSE)
Platform Difficulty (PDIF)
Personnel Capability (PERS)
Personnel Experience (PREX)
Facilities (FCIL)
Schedule (SCED)
Created by- Karishma Gupta (2012CA55) Ref: Software Engineering By K.K. Aggarwal & Yogesh Singh
MNNIT ALLAHABAD, INDIA

34. Data for the Computation of B (Scalar Factor)
Scaling Factors
Very Low
Low
Nominal
High
Very High
Extra High
Precedentness
6.20
4.96
3.72
2.48
1.24
0.00
Development Flexibility
5.07
4.05
3.04
2.03
Architecture/ Risk Resolution
7.07
5.65
4.24
2.83
1.41
Team Cohesion
5.48
4.38
3.29
2.19
1.10
Process Maturity
7.80
6.24
4.68
3.12
1.56
Created by- Karishma Gupta (2012CA55) Ref: Software Engineering By K.K. Aggarwal & Yogesh Singh

35. Calculate the scalar factor B
If B=1.0, then Linear relationship b/w Effort & Size. If B , then Non-Linear relationship b/w Effort & Size. If B<1.0, then the rate of increase of effort decreases as the size of the product increases. If B>1.0, then the rate of increase of effort increases as the size of the product increases.
B = * (Sum of rating on scaling factors for the project)
When all the scaling factors of a project are rated as extra high,
then the best value of B= 0.91 (for COCOMO II.2000)
when all the scaling factors of a project are rated as very low,
Then the worst value of B= 1.23 (for COCOMO II.2000)
Hence, the value of B may vary from 0.91 to 1.23
Created by- Karishma Gupta (2012CA55) Ref: Software Engineering By K.K. Aggarwal & Yogesh Singh

36. Early Design Model: Example
Question: A software project of application generator category with estimated 50 KLOC has to be developed. The scale factor (B) has low precedentness, high development flexibility and low team cohesion.
Other factors are nominal. The early design cost drivers like platform difficult (PDIF) and Personnel Capability (PERS) are high and others are nominal.
Calculate the Effort in person-months for the development of the project.
Early Design Cost Drivers
Extra Low
Very Low
Low
Nominal
High
Very High
Extra High
RCPX
0.73
0.81
0.98
1.0
1.30
1.74
2.38
RUSE -
0.95
1.07
1.15
1.24
PDIF
0.87
1.29
1.81
2.61
PERS
2.12
1.62
1.26
0.83
0.63
0.50
PREX
1.59
1.33
1.12
0.71
0.62
FCIL
1.43
1.10
SCED
1.14
Created by- Karishma Gupta (2012CA55) Ref: Software Engineering By K.K. Aggarwal & Yogesh Singh

37. Solution :
B = * (Sum of rating on scaling factors for the project)
= * ( )
= (20.29)=1.1129
= 2.5 * (50) = Person-months
here A=2.5 (for COCOMO II.2000) predefined
The 7 cost drivers are:
PDIF = high (1.29) PERS = high (0.83)
RCPX = nominal (1.0) RUSE = nominal (1.0)
PREX = nominal (1.0) FCIL = nominal (1.0)
SCEO = nominal (1.0)
= * [1.29 x 0.83]
= x 1.07
= Person months
Created by- Karishma Gupta (2012CA55) Ref: Software Engineering By K.K. Aggarwal & Yogesh Singh

38. Post Architecture Model
Most detailed estimation model.
Used when a software life cycle architecture has been completed.
Used in the development and maintenance of software products in the application generators, system integration or infrastructure sectors.
Lines of Codes Counting Rules
Function Points
Cost Drivers
Where
EM : Effort multiplier which is the product of 17 cost drivers.
PMnominal = Effort of the project in person months.
Created by- Karishma Gupta (2012CA55) Ref: Software Engineering By K.K. Aggarwal & Yogesh Singh

39. Cost Drivers of Post Architecture
Product Attributes
Required Software Reliability (RELY)
Database Size (DATA)
Product Complexity (CPLX)
Documentation (DOCU)
Required Reusability (RUSE)
Computer Attributes
Execution Time Constraint (TIME)
Platform Volatility (PVOL)
Main Storage constraint (STOR)
Personnel Attributes
Analyst Capability (ACAP)
Personnel Continuity (PCON)
Programmer Experience (PEXP)
Programmer Capability (PCAP)
Analyst Experience(AEXP)
Language & Tool Experience (LTEX)
Project Attributes
Use of Software tools (TOOL)
Required development schedule (SCED)
Site Locations & Communications Technology b/w sites (SITE)
Created by- Karishma Gupta (2012CA55) Ref: Software Engineering By K.K. Aggarwal & Yogesh Singh

40. Added Cost Drivers Deleted Cost Drivers 7 cost drivers 5 Cost Drivers
DOCU
RUSE
PVOL
PLEX
LTEX
PCON
SITE
5 Cost Drivers
VIRT
TURN
VEXP
LEXP
MODP
Created by- Karishma Gupta (2012CA55) Ref: Software Engineering By K.K. Aggarwal & Yogesh Singh

41. 17 Cost Drivers Cost Drivers Very Low Low Nominal High Very High
Extra High
RELY
0.75
0.88
1.00
2.48
1.24
0.00
DATA
0.93
2.03
CPLX
2.83
1.41
RUSE
0.91
2.19
1.10
DOCU
0.89
0.95
3.12
1.56
TIME
1.11
1.31
1.67
STOR
1.06
1.21
1.57
PVOL
0.87
1.15
1.30
ACAP
1.50
1.22
0.83
0.67
PCAP
1.37
1.16
0.74
PCON
0.92
0.84
AEXP
0.81
PEXP
1.25
1.12
LTEX
TOOL
0.86
0.72
SITE
0.78
SCED
1.29
Created by- Karishma Gupta (2012CA55) Ref: Software Engineering By K.K. Aggarwal & Yogesh Singh

42. Schedule Estimation Size Measurement
Development time can be calculated using PMadjusted as a key factor and the desired equation is:
Where
= constant, provisionally set to 3.67, B = Scaling factor
TDEVnominal = calendar time in months with a scheduled constraint
PMadjusted = Estimated effort in Person months (after adjustment)
Size Measurement
Size can be measured in any unit and the model can be calibrated
accordingly. However, COCOMO II details are:
Application composition model uses the size in object points.
The other two models use size in KLOC.
Created by- Karishma Gupta (2012CA55) Ref: Software Engineering By K.K. Aggarwal & Yogesh Singh

43. Post Architecture: Example
Ques: A software project of application generator category with estimated 50 KLOC has to be developed. The scale factor (B) has low precedentness, high development flexibility and low team cohesion. The identified 17 Cost drivers are high reliability (RELY), very high database size (DATA), high execution time constraint (TIME),
very high analyst capability (ACAP), high programmers capability (PCAP).
The other cost drivers are nominal.
Calculate the effort in Person-Months for the development of the project.
Here B =
PMnominal = Person-months
= x (1.15 x 1.19 x 1.11 x 0.67 x 0.87)
= x 0.885
= Person-months
Solution :
Created by- Karishma Gupta (2012CA55) Ref: Software Engineering By K.K. Aggarwal & Yogesh Singh

44. Created by- Karishma Gupta (2012CA55). Ref: Software Engineering By K
Created by- Karishma Gupta (2012CA55) Ref: Software Engineering By K.K. Aggarwal & Yogesh Singh

45. Final Word
“The models are just there to help, not to make the management decisions for you.” --Barry Boehm
Ref:

46. References
Software Engineering (Third Edition) By K.K.Aggarwal & Y. Singh
Fundamentals of Software Engineering (Third Edition) By Rajib Mall
Software Engineering , 6th Edition By Ian Sommerville
Software Engineering (Sixth Edition) by Roger S. Pressman
mo.pdf

47. Thank You