1. Software Cost Estimation For Component Based Fourth-generation-language Software Applications
지능형시스템 연구실
김정민

2. Contents Introduction Overview of The Existing Models
Component-based 4GL Applications
Proposed Method
Empirical Validation of The Proposed Method
Conclusion
Proposal

3. Introduction Accurate cost estimation is important
Help to classify and priorities development projects
Determine what resources to commit to the project and how well these resources will be used
Assess the impact of changes and support re-planning
Projects can be easier to manage and control when resources are better matched to real needs
Customers expect actual development costs to be in line with estimated costs
Cost estimation issues
Which software cost estimation model to use?
Which software size measurement to use – lines of code(LOC), function points (FP) or feature point?
What is a good estimate?

4. Overview of The Existing Models
SLOC (Source lines of code) based models
Calculating expected SLOC
Smallest possible SLOC – a
Most likely SLOC – m
Largest possible SLOC – b
n: total number of pieces
α: the marginal cost per thousand LOC (KLOC);
β: an exponent of the KLOC and gamma,
γ: the additional fixed cost of the project

5. Overview of The Existing Models
FP models
Measure of the amount of function provided by the software system
Originally developed as an alternative to SLOC to measure productivity in the later stages of software development
Provides fives categories of functions to count: external inputs, external outputs, external inquiries, external interfaces and internal files
ci: list of 14 general system characteristics

6. Overview of The Existing Models
FP models
General system characteristics
GSC
Brief Description
Data communications
How many communication facilities are there to aid in the transfer or exchange of information with the application or system?
Distributed data processing
How are distributed data and processing functions handled?
Performance
Was response time or throughput required by the user?
Heavily used configuration
How heavily used is the current hardware platform where the application will be executed?
Transaction rate
How frequently are transactions executed daily, weekly, monthly, etc.?
On-Line data entry
What percentage of the information is entered On-Line?
End-user efficiency
Was the application designed for end-user efficiency?
On-Line update
How many ILF’s are updated by On-Line transaction?
Complex processing
Does the application have extensive logical or mathematical processing?
Reusability
Was the application developed to meet one or many user’s needs?
Installation ease
How difficult is conversion and installation?
Operational ease
How effective and/or automated are start-up, back-up, and recovery procedures?
Multiple sites
Was the application specifically designed, developed, and supported to be installed at multiple sites for multiple organizations?
Facilitate change
Was the application specifically designed, developed, and supported to facilitate change?

7. Component-based 4GL Applications
Cost estimation of fourth-generation languages
Fourth-generation languages
Component based languages which provide a rich set of components
Visual Basic, VB.Net and Visual C#
User can develop an application without writing single line of code
When there is no line of code, SLOC based models cannot be used
FP metrics can be used but the function categories defined for FP metrics do not exactly apply on 4GL applications

8. Component-based 4GL Applications
Koten and Grey’s model for data centered 4GL
The minimal set of specifications completed for a software system
Entity relationship diagram (ERD)
Functional hierarchy diagram (FHD): functional specifications of the system’s user-interface components
The system’s database is automatically generated from the ERD
User interface components: forms, reports and graphs
Developers’ effort would be primarily spent performing the two tasks
Creating each component by using various readymade graphical user interface items such as text boxes and combo boxes
Adding code to the items
This model was developed to predict the software effort only for that software where data is accessed from database to forms, reports and graphs
Use Bayesian Network for cost estimation
For non-database application, this model is not suitable

9. Component-based 4GL Applications
Riquelme’s model for database-oriented software
Analyses the relationship between a set of metrics for 4GL programs and the maintenance time for such programs which uses SQL statements
Parameters of this model
NS = total number of Select instructions in the considered program.
NI = total number of Insert instructions in the considered program.
ND = total number of Delete instructions in the considered program.
NU = total number of Update instructions in the considered program.
NT = total number of used Tables in the considered program.
NN = total number of Nestings in the considered program.
Where = total number of Where clauses in the considered program.
Suitable only for database applications

10. Component-based 4GL Applications
Morgan Peeples’s model
Calculates level of effort (LOE) of a project
These calculations seem very illusive because complexity of development of each and every component has been taken as equal
In practice, the LOE required to develop one form will not be equal to another one as the complexity of development will vary
Same is true for reports, tables and modules
LOEp: the number of person days of effort it takes to develop a software application project
a: the y intercept
b1: the number of person days for one form F;
b2: the number of person days for one report R;
b3: the number of person days for one table T;
b4: the number of person days for one module M

11. Proposed Method Nominal effort for a given size project
Size: units of thousands of source lines of code (KSLOC)
A: Constant
B: scale factor

12. Proposed Method
Modern software development environments are aggregates of forms, reports, tables and modules
Forms: objects for interaction or navigation by the user
The 4GL tool provides templates for the developer to use.
The form templates can be used as menus that move the user through the application, or for use as data entry, querying screens or other forms required for the application.
A form is actually a collection of different components.
Reports: objects that retrieve data from tables, to format and present that data to the user
The 4GL tool provides an easy way to use interface and readymade products for the developer to tailor and create specialized reports
Some reports may be simple but some may be more complicated as they need extensive coding as well as higher level complicated database queries and stored procedures

13. Proposed Method
Modern software development environments are aggregates of forms, reports, tables and modules
Tables: objects created to store data.
The 4GL tool provides features for the developer to define and generate data definition language and create tables automatically from design models
The level of complexity also varies as some table may require only a few fields, whereas other will require hundreds of fields with integrity constraints.
Modules: portion of a software development application that cannot otherwise be delivered, except to be created
Might be computational algorithms, transaction handling, processes and code written for different events.

14. Proposed Method Size of the software
SizeC: size of components (forms, reports and tables)
Sizem: size of Modules in KSLOC
SizeF: the sum of sizes of all forms
SizeR: the sum of size of all reports
SizeT: the sum of size of
all tables in database
sum of size of its components

15. Empirical Validation of The Proposed Method
We applied the proposed method on 19 projects

16. Empirical Validation of The Proposed Method
We applied the proposed method on 19 projects
Result of proposed method

17. Empirical Validation of The Proposed Method
We applied the proposed method on 19 projects
Result of van Koten’s method

18. Conclusion Proposed approach gave a significant level of accuracy
Further research
Apply in larger projects is required
It is also required to identify more components as only four structural components, that is, forms, reports, tables and modules
Calibration is likely to be essential in order to improve the level of accuracy
This research will be a new direction for estimating cost of software application using component-based 4GL

19. Proposal 논문의 개선(안) Cost 계산 시 고려할 factor 추가 Cost 계산 모델 수정
Component별 라인 수에 쏠림이 있는지 고려
개발에 사용된 언어도 PM 계산에 반영
Cost 계산 모델 수정
Size 계산시 요소 별 가중치 부여
Size와 PM의 관계 학습 시 다른 학습 모델 사용 고려