Improving Estimation Organizational Maturity

Achieving project success and productivity improvements with mature estimation practices

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Contents

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Estimation Organizational Maturity Model (EOMM) What is the EOMM?

The 5 stages of Estimation Maturity

Key differences between Level 1 and Level 2

Achieving Level 2 maturity using Function Points Introducing Function Points

Function Points across the project lifecycle

Associated Metrics

Resources

What is the EOMM?

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Proposed by Dan Galorath, chief architect and developer of SEER, software cost estimation tool Defines 5 levels of estimation maturity

Most organizations are at Level 1

Provides a roadmap to Improve estimation accuracy

Improve project predictability

Measure and improve productivity

Level 0Informal

Manual Estimation

with no process

Level 1Direct Task

Estimation (Work Breakdown Structure)

Spreadsheets Ad Hoc Process

Level 2Formal Sizing (e.g. Function

Points)

Direct Task Estimation

Simple Model (Size*Productivit

y)

Some Measurement and

Analysis)

Informal Process

Level 3 Formal SizingRobust

parametric Estimation

Estimation vs Actual

capture

Formalized multiple estimate process

Rigorous measurement and Analysis

Risk Management

Repeatable Process

Level 4 Formal Sizing Repeatable Process

Robust Parametric Estimating

Rigorous Measurement and Analysis

Parametric Estimation

with Tracking and control

Risk Management

Process Improvement

via lessons learned

Level 5 Formal Sizing Repeatable Process

Robust Parametric Estimating

Rigorous Measurement and Analysis

Parametric Estimation

with Tracking and control

Risk Management

Continuous Process

Improvement

The 5 Stages of Estimation Maturity

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Source: Galorath.com

Key Differences between Levels 1, 2 and 3

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Level 1 is based on Work Breakdown Method

Level 2 is based on formal software sizing Size can be expressed in units like Lines of Code (LOC), feature points,

use case count or Function Points

Introduces basis for organizational productivity measurement for application development

Level 3 lays the basis for continuous process improvement Uses parametric estimation (like COCOMO)

Process improvement leads to productivity gains

According to Gartner, just moving up from Level 1 to 2 reduces estimated vs actual variance by 50%

Difference Between Formal Sizing and WBS

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Formal Sizing: Key Features Effort = Size / Productivity

Size is measured from a user’s perspective

Productivity depends on technology/skill level/ organization environment and other factors

A large number of secondary metrics can be predicted

Large industry database available to benchmark

WBS: Key Features Directly provides estimates in person hours (or days/months)

Based on developer’s perspective, varies by person

Productivity is hidden and cannot be verified, measured or improved

Does not factor in organizational productivity

Parametric Estimation

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Level 3 introduces parametric based estimation Factors in a number of attributes that determine productivity

COCOMO is an example of a parametric based estimation technique

Since productivity is broken down into smaller attributes, it is easier to improve productivity by managing those attributes

How to measure software size

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Number of sizing options available Function Points

Others like SLOC, feature points, use case count

Function Points Industry Standard, developed by IBM in 1979

Rich industry database base

Can be used to compare projects and applications

Rich knowledge base of secondary metrics available

Moving to Level 2…introducing Function Points

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Using Function Point (FP) sizing at project start and during execution can assist planning accuracy, manage and improve project delivery

This applies only to projects where FP sizing can be used (Application Development and Enhancements, no infrastructure projects)

Using Function Points across the project lifecycle

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Phase Key Derived Metrics Common across phases

Scoping High Level Effort, Cost and Duration, Risk Assessment

• Productivity• Drive Standardization

Requirements Baseline Effort, Cost and Duration

Design and Development Scope Creep

Testing Defect Count and Rework Effort

Maintenance Defect Prediction, Cost of Maintenance

• Cost• Duration• Scope Creep• Risk Assessment• Defect Prediction• Rework Effort

Size Application(FP)

Historical Data

Scoping

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Take Decisions Early WBS based estimates take long to compute as they need inputs from many teams

FP Sizing is a lot quicker and helps negotiate scope w.r.t duration, scope and cost

Estimating with limited information Quick FP and assumptions can help in determining initial FP count

Historical data for duration and cost can be leveraged

Determine size by functional modules and provide an overall cost map (size is a good measure of cost)

Other benefits Assess Replacement Impact Compare FP size of existing and replacement systems

Compare Vendor Solutions

Requirements

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Determine baseline Effort, Duration, Cost

Phase wise planning using historical data

Evaluate Requirements Completion (e.g. use industry or own historical data)

Determine Risk (e.g. Projects less than 500 function points have a risk of failure of less than 20% while those over 5000 function points which have a probability of cancellation close to 40%.)

Quantify scope for phased development using quantified ‘what if ’ scenarios

Development and Testing

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Determine FP count at phase end to Measure scope creep

Compare with baseline FP count at end of requirements phase

Predict Defect Count at each phase

Defect prediction can be used to assess project risk to meet expectations

Associated Metrics: Effort and Duration

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Barry Boehm’s formula to compute duration as a function of effort

Calendar Months (A) = 2.5 x Person Months 1/3

Customize this equation based on historical data:– Calendar Months = A + coefficient

Defect and Productivity Related Techniques

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There are techniques that can be used (and improvised) for defect prediction when sufficient historical data is not available Count of UAT test cases = 1.2 x FP

Total count of test cases = FP1.2

Productivity COCOMO can be used to fine tune productivity numbers

Source

Resources

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Galorath Inc

SPR Estimation Resources

Uses and Benefits of Function Points

COCOMO

Defect Prediction and Prevention

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Thank you

Bhupinder Singh

http://ca.linkedin.com/in/bhupindersingh