unleashing the power of function point analysis - ifpug

1Copyright CHARISMATEK Software Metrics IFPUG San Diego 2004

Paul RadfordCHARISMATEK Software Metrics

UNLEASHING THE POWER OF FUNCTION POINT ANALYSIS

FPA across the Software Lifecycle - the critical model


CHARISMATEK Software MetricsWho We Are and What We Do …

• Australia’s flagship company for the provision of software tools and consulting and training services in the area of functional size measurement:

• Software Sizing, Estimating & Benchmarking• Contracts & Suppliers• Software Process Improvement• Software Capability Assessment and Gap Analysis• Portfolio Management

• Developers of the Function Point WORKBENCH™, the world’s leading software tool supporting the Function Point Analysis technique for sizing and evaluating software.

• In the business of software metrics since 1991 and based in Melbourne.


Interest in Functional Sizing Measures… A Truly International Coverage!

USA

Canada

Denmark

UK

India

Brazil

SpainSwitzerland

South Africa

United Arab Emirates

Germany

Italy

Uruguay

FranceJapan

New Zealand

Netherlands

Australia

Argentina

Mexico Trinidad & Tobago

China

PolandRussia

Lithuania

EgyptHong KongSouth KoreaGreece

Austria

Indonesia

Turkey

Singapore

Bulgaria

Iceland

Croatia

Belgium

Thailand

Chile

PakistanPortugal

Sweden

Romania

Philippines

Panama

Finland

Czech Republic

Venezuela

MalaysiaSaudia Arabia


Functional Size MeasurementCritical Advantages!

Software Project

Software Product

⇒ focuses on the functionality the softwaredelivers to its users

⇒ is independent of how the software is builteg language, technology, methodology

⇒ can be determined early in the developmentlife cycle

⇒ is a reliable predictor of effort - and hence cost -to build and support the software

⇒ provides a Standard Notation and Definition based upon an objective approach for software sizing (IFPUG and ISO Standards)

Software Functional Size

650 Function PointsFunctional Size Measurement

Functional Size is a measure of software size that:


Functional Size MeasurementOne Common Language!

Software Project

Software Product

⇒ focuses on the functionality the softwaredelivers to its users

⇒ provides a definition, within a known technical environment, that is meaningful and relevant to the IT Developer



Functional Size is a measure of software size that:

ONE MODEL

ONE LANGUAGE

IT <-> BUSINESS


Feasib

ilityStud

yReq

uirem

ents

Analys

is Design

Constr

uctio

nTes

ting

Imple

mentat

ion

Enhan

cemen

t

Produc

tion

ProjectEstimation

ScopeManagement

RequirementsAssessment

FunctionalBaseline

StatusMonitoring

ComplianceAssessment Enhancement

Projects

Support ResourceForecasting

The role of Functional Size Measurementin the Software Development Life Cycle

Functional Size Measurement- a Role in a Range of Activities Throughout the Software Development Life Cycle

- a Critical Component of Successful Software Development


Functional Size MeasurementThe Basis for Software Management

Software Project

Software Product

⇒ A Structure for Definition

⇒ A Reliable Basis for Estimation

⇒ A Basis for Communication/Negotiation

⇒ A Framework for Project Control

⇒ A Means for Assessing Impact of Change

⇒ An Integrated Link to Support Metrics



The Quantified Functional Model provides:


Assessing, Clarifying & NegotiatingRequirements

PreliminaryFunctional Model:

First Cut. Consists of:• Some clearly specified user

functions • Other user functions requiring

clarification

• Basis for negotiation on project functionality

• Underwrites the business case

FunctionRequiring

Clarification

Early Life-CycleEstimates

Multiplierfor

No of Instances of a Function

Indicative Functional Size:• Basis for very early

life-cycle estimation

FeasibilityStudy

IndicativeProject

Size


Functionality RequiringClarification from Client

Requires Clarificationlarge!

Specified

Requires Clarificationsmaller!

SpecifiedHIGHER RISK! LOWER RISK!

Rework

Assessing, Clarifying & Negotiating Requirements RequirementsAnalysis


A Software Project Functional Baseline

Detailed Functional Model:• All agreed user functions

assessed, classified and sized• Cross references to other

project documentation• Sharing the Vision:

• Mutually Understood• Agreed baseline for estimation,

tracking and control and scope management

• Auditable, verifiable and defensible

ProjectSize

Sub-System

Size

Fully Assessed Count:• Entire project• Project sub-systems• Alternative project views

RequirementsAnalysis


Tracking Requirements RequirementsAnalysis

In this example, user functions arecross-referencedto their use casespecifications.

In order to trackRequirements, each function should be cross referenced to specifications and work products.


Estimating Project Effort and Cost

Multiple ProductivitySinks & Rates:

• Development languages and environments:

eg Java 14.2 Hrs / FP,.NET 17.3 Hrs / FP,SQL Server 7.5 Hrs / FP

• Assign user functions to productivity sinks to develop detailed estimates

Productivity Sinks& Rates (Hrs / FP)

Estimation

Effort& Cost Estimates


Estimating Project Effort and Cost

“What productivity will we achieve on the planned project?”Accounting Based Upon:

• Own History• Design Approach• Industry Benchmarks• Tools/Consultants Expertise

Productivity Sinks& Rates (Hrs / FP)

Further Refined Project Views:• Functional priorities:

eg essential versus optional• Development releases:

eg 1st, 2nd, 3rd releases

Cross Validation:• Task based estimate comparison

Estimation

Effort& Cost Estimates


Effort and CostEstimates

Programming Environment basedProductivity Sinks and Rates

EstimationEstimating Project Effort & Cost


EstimationEstimating Project Effort & Cost

Effort and CostEstimates


Modeling Enhancement Projects

EnhancementFunctional Model:

• Functions added, changed, deletedor of interest to regression testingApplication Functions

Added or Changed byEnhancement Project

EnhancementProject Size

Application Baseline:• Automatically maintained after

each enhancement• Represents an application’s

current functionality and size

Enhancement

EnhancementFunctional Size:

• Size of enhancement project• Size of test scope• Size of application baseline

after project completion

Enhancement Size 66Test Scope Size 89Application Size 173after Enhancement


Managing Project Scope

Project Scope Monitoring:• Assess scope and size of project at

major milestones and update the model

• Compare actual versus expectedsize and scope

FunctionalityAdded during

Detailed Design

Early Scope ‘Blowout’ Identification:• Identify unacceptable scope increase

early• Highlight magnitude and nature of

scope increaseImpact of Scope ChangeAssessment:

• Estimate potential additional development costs and schedule increase

• Renegotiate project scope• Understand where and why change

occurs

Requirements toImplementation

PhaseWhen Function

Introduced


UnacceptableProject Size andScope Increase

New Project Sizeafter Negotiationand Rescoping

Requirements toImplementationManaging Project Scope


Monitoring & Controlling Project Status

Project StatusFunctional View:

• Assess the status of user functions within a project phase

• Alternative to traditional ‘percentage complete’view of project status

Enhanced Developer and Client Communication:

• Easily maintained by developers /technical staff

• Easily understood by clients / business

Requirements toImplementation

ConstructionPhaseStates

CurrentFunctionStatuswithin

ConstructionPhase


Requirements toImplementationMonitoring & Controlling Project Status

Snapshot of theCurrent Functional Size

within eachConstruction Phase State


Project Counts

Audit, Internal Benchmarking, Patterns

Software Development

Life Cycle PhasesProjects

Feas

ibili

ty

Req

uire

men

ts

Exte

rnal

Des

ign

Inte

rnal

Des

ign

Impl

emen

tatio

n

Prod

uctio

n

Core Functions

Sales Reports

Security

0

100

200

300

400

500

600

700

Historical Analysis/DrilldownCounts for an Application System

Application Counts


Benchmarking, Productivity AnalysisCompleting the Cycle

Application/Environment Benchmarks & Comparative Analysis

Development BenchmarksCapability Analysis• Process• Personnel• EnvironmentSizeProductivity Sinks

Support BenchmarksCapability AnalysisSizeApplication Complexity, Age, Volatility, Data & Client Volume

unleashing the power of function point analysis - ifpug

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