1. Description of Function
Point Analysis

2. Agenda
 Introduction
 What is a Function Points?
 How to count Function Points?
 Why use Function Points?
 Summary

3. Introduction
 Importance of software measurement
 Main methods of software measurement:
 Function Points
 LOC (Lines of Code)
 Wideband-Delphi methodWideband-Delphi method
 Fuzzy-logic methodFuzzy-logic method
 Probe method
 Standard component
……

4. What is a Function Points?
 The history of Function Points:
 Introduced by Allan Albrecht (IBM)
 Inherited by IFPUG (International Function
Points Users’ Group)

5. What is a Function Points?(2)
 FP are a unit measure for software
 Easy to understand the size of software
 Easy to predict the cost of software
 Easy to plan the schedule of software

6. What is a Function Points?(3)
 5 basic elements of Function points
 EI: External Input
 EO: External Output
 EQ: External Query
 ILF: Internal Logic File
 EIF: External Interface File

7. How to count Function Points?
 7 steps to count Function Points
 Determine the type of Count
 Identify Counting Scope and Application
Boundary
 Count Data Functions
 Count Transactional Functions
 Determine Unadjusted Function Point Count
 Determine Value Adjustment Factor
 Calculate Adjusted Function Point Count

8. Determine the type of Count
 Ultimate functions the developers provide
 Functions to update the existed software
 Functions to use and maintain software

9. Identify Counting Scope and
Application

10. Count Data Functions
 Two types of Data Functions
 Internal logic File
 Logical group of data maintained by the
application (e.g., Employee file)
 External Interface File
 Logical group of data referenced but not
maintained (e.g., Global state table)

11. Count Transactional Functions
 Three types of Transactional Functions
 External Input
 Maintains ILF or passes control data into the
application
 External Output
 Formatted data sent out of application with added
value (e.g. ,calculated totals)
 External Inquiry
 Formatted data sent out of application without
added value

12. Determine Unadjusted Function Point
Count

13. Determine Value Adjustment Factor
 14 Value Adjustment Factors
 Data communication
 Distributed data processing
 Performance
 Heavily used configuration
 Transaction rate
 Online data input
 End user efficiency

14. Determine Value Adjustment
Factor(2)
 14 Value Adjustment Factors
 Online update
 Complex processing
 Reusability
 Installation ease
 Operational ease
 Multiple sites
 Facilitate change

15. Determine Value Adjustment
Factor(3)
 Based on the 14 general system
characteristics ,get the Value Adjustment
Factor (VAF)

16. Calculate Adjusted Function Point
Count
 FP = UFP * VAF
 The ultimate Function Points are determined
by Unadjusted Function Points and the Value
Adjusted Function Point

17. Why use Function Points?
 Technology Independence
 Consistency and Repeatability
 Data Normalization
 Estimating and Comparing
 Scope and Expectations

18. Summary
 Introduction
 What is a Function Points?
 How to count Function Points?
 Why use Function Points?