Galorath Incorporated 2004
AccuScope –A Tool For Relative Comparisons
Lee Fischman & Kenneth FongGalorath Incorporated
SCEA 2004Manhattan Beach, CA
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Presentation OutlinePresentation Outline
AccuScope’s Role
Key Features
Four Step Sizing Process
Accuracy
Risk-driven estimates
Size Anything
Key Enabling Features• Shareable Repository of Known Items• Cut and Paste with Other Applications
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AccuScope’s Role
Scope Software and Other Items
Earlier – provide reasonable size ranges prior to a detailed understanding of project More Accurately – relative knowledge often results in more accurate up front estimates vs. other methods
More Efficiently – assist the sizing process with features making it easier and possible under more circumstances
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Key Features
Mathematically Sound• Incorporates proven methods plus Galorath implementation• Utilizes pair-wise comparisons against a number of known and unknown items • Uses these comparisons to estimate unknown items
Repository of Known Items • Provides access to a repository of enterprise information on completed items • Can reside on your desktop or be deployed across an organization
Analogies • Provide “logical patterns” for sizing new items from typical functionality • Based on in-house experience, provides a common basis for characterizing scope
Smorgasbord of Quantitative Metrics• Source Lines of Code (SLOC)• Function Points• Function-Based Sizing• And many more customizable metrics…
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Four Step Sizing Process
3. Perform various expert judgment comparisons
1. Identify Items to size
2. Choose references or analogies for comparison
4. View / Use results
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Step 1: Identify Items To Size
Estimated items are those which will be sized.
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Step 2: Choose References To Size
Reference items are those from which comparisons are made.
These items can be entered manually or obtained from a repository.
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And (Or) Choose an Analogy
Analogies are optional.
Analogies are reference items based on past patterns.
Choose from various sets of analogies, each representing different sizing perspectives, or create your own manually.
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Step 3: Ready For Comparisons
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Step 3a: Compare Known & Unknown Items
Expert judgment establishes the relative size between ‘Tristate Net’ and ‘New Backup Site’.
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Step 4: View / Use Results
AccuScope lets you view sizing information and estimates using a variety of reports and charts.
Reports are presented using different metrics depending on the size metric (source lines of code, function points, etc.)you are working with.
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AccuScope’s AccuracyAccuScope’s Accuracy
For above test:Perfect information: no errant comparisonsEach bar above represents 250 randomized trials5 reference items compared to 3 estimated items7 stop slider range, 3 above ‘equal’ and 3 below
Accuracy of 'Likely' Outcome Under Different Scenarios
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
Distributions: left-skewed, centered, right-skewed
MR
E
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Factors Affecting AccuracyFactors Affecting Accuracy
Number of items being compared – more is better, since that places fewer constraints on information available to the algorithm.
Number of reference items – 1 can be enough, > 1 will improve results when comparisons are imperfect.
Appropriateness of reference items – a sensible range of items spanning the same range as estimated items is helpful although not required.
User’s assessments – the more accurate, the better. This is by far the most significant factor.
Granularity of comparisons – more granular is more accurate BUT this results in increasing ‘cognitive overload’ for the user.
Mapping between qualitative ratings and underlying ratios – the user’s conception of ‘Big’, ‘Bigger’, etc. should match the ratios they map to.
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Least / Likely / Most RangesLeast / Likely / Most Ranges
Comparison Ratio Ranges
0.10
1.00
10.00
MuchBigger
Bigger SlightlyBigger
Equal SlightlySmaller
Smaller MuchSmaller
Qualifier Label
Com
paris
on R
atio
Ratios have a range – so that estimates capture the edge of intuition between (for example) ‘Slightly Bigger’ and ‘Bigger’.
User entries can have a range – so that the user can establish bounds on level of understanding.
Reference sizes can be entered as a range – in case the size count is imperfect.
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Range of Inputs CreatesRange of Inputs CreatesEstimates Across A RangeEstimates Across A Range
Size ByComparison
Inputs* reference values* slider entries* comparison ratios
Lower
Likely
Highest
Lower
Likely
Highest
OutputsEstimated items
as a range
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Configurable For ManyConfigurable For ManyEstimating ChallengesEstimating Challenges
Configured out of the box for software estimating, AccuScope may also be used to:
• rank risk• calculate hardware weight• determine colleagues’ ages• and so on…
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Size Anything Using This Approach
Estimates based on past known items, analogies, manually created reference items, etc.Can size ANYTHING:• Hardware weight• Software size• Program office staff size
AccuScope can access a repository of reference items, analogies can be customizedEstimates are output as a range, for use in risk-based estimatingAnything can be sized by relative analysisPercentage or qualifier (“Smaller”, “Larger”, est.) ratings
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Repository
Uses a variety of database types, including SQL Server or simpler, client-side solutions
Repository may be shared across the enterprise, so many users can access the same information
Online / offline modes
Easy editing of repository entries
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Cut and Paste With Other ApplicationsCut and Paste With Other Applications
Copy to and fromMicrosoft Excel
and other applications
Copy / pasteintegration
with SEER-SEM
Microsoft ExcelAccuScope
SEER-SEM
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Summary
AccuScope enables:
Reasonable size ranges prior to a detailed understanding of the project
Sharing of corporate knowledge
Customization to a wide variety of estimating challenges
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