FUNCTION POINT ANALYSIS & ESTIMATION
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Transcript of FUNCTION POINT ANALYSIS & ESTIMATION
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www.davidconsultinggroup.com
FUNCTION POINT ANALYSIS &
ESTIMATION
Gurpreet Singh
M.Tech CSE Part Time – 3rd Semester
Roll No. 17 & Regd. No. 40800066
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What is Function Point Analysis (FPA)?
• It is designed to estimate and measure the time, and thereby the cost, of developing new software applications and maintaining existing software applications.
• It is also useful in comparing and highlighting opportunities for productivity improvements in software development.
• It was developed by A.J. Albrecht of the IBM Corporation in the early 1980s.
• The main other approach used for measuring the size, and therefore the time required, of software project is lines of code (LOC) – which has a number of inherent problems.
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• Inputs• Outputs• Inquiries• Internal Logical Files• External Interface Files
Input Inquiry
Output
InternalLogical
Files
External Interface
File
Five key components are identified based on logical user view
Application
The Function Point Methodology
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General System CharacteristicsData Communication On-Line Update
Distributed Data Processing Complex Processing
Performance Objectives Reusability
Heavily Used Configuration Conversion & Install Ease
Transaction Rate Operational Ease
On-Line Data Entry Multiple-Site Use
End-User Efficiency Facilitate Change
The final calculation is based upon the Unadjusted FP count X VAF
14 Optional General Systems Characteristics are evaluated and used to compute a Value Adjustment Factor (VAF)
The Function Point Methodology
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What is Function Point Analysis (FPA)?
These function-point counts are then weighed (multiplied) by their degree of complexity:
Simple Average ComplexInputs 2 4 6Outputs 3 5 7Files 5 10 15Inquires 2 4 6Interfaces 4 7 10
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What is Function Point Analysis (FPA)?
A simple example:
inputs3 simple X 2 = 6 4 average X 4 = 161 complex X 6 = 6
outputs6 average X 5 = 302 complex X 7 = 14
files5 complex X 15 = 75
inquiries8 average X 4 = 32
interfaces3 average X 7 = 214 complex X 10 = 40
Unadjusted function points 240
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What is Function Point Analysis (FPA)?
Continuing our example . . . Complex internal processing = 3Code to be reusable = 2High performance = 4Multiple sites = 3Distributed processing = 5
Project adjustment factor = 17
Adjustment calculation:Adjusted FP = Unadjusted FP X [0.65 + (adjustment factor X 0.01)] = 240 X [0.65 + ( 17 X 0.01)] = 240 X [0.82] = 197 Adjusted function points
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PROJECTSIZE
X X RISKFACTORS
PROJECTCOMPLEXITY
DEFINITION CAPABILITY ESTIMATE
Schedule
Effort Costs
REQUIREMENT
FUNCTION POINT ANALYSIS
Project Estimation
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Conclusions
• Project Management can be successful • Requirements can be managed • Projects can be sized • Performance can be successfully estimated • Process improvement can be modeled• Measurement can be accomplished
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Thanks