Description of Function Point Analysis

Agenda

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

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

……

What is a Function Points?

The history of Function Points: Introduced by Allan Albrecht (IBM) Inherited by IFPUG (International Function

Points Users’ Group)

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

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

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

Determine the type of Count

Ultimate functions the developers provide Functions to update the existed software Functions to use and maintain software

Identify Counting Scope and Application

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)

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

Determine Unadjusted Function Point Count

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

Determine Value Adjustment Factor(2) 14 Value Adjustment Factors

Online update Complex processing Reusability Installation ease Operational ease Multiple sites Facilitate change

Determine Value Adjustment Factor(3) Based on the 14 general system

characteristics ,get the Value Adjustment Factor (VAF)

Calculate Adjusted Function Point Count FP = UFP * VAF The ultimate Function Points are determined

by Unadjusted Function Points and the Value Adjusted Function Point

Why use Function Points?

Technology Independence Consistency and Repeatability Data Normalization Estimating and Comparing Scope and Expectations

Summary

Introduction What is a Function Points? How to count Function Points? Why use Function Points?