George Ukkuru
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Transcript of George Ukkuru
Wideband Delphi Technique
George Ukkuru
Introduction
Consensus based approach for estimation
Developed in the 1940’s at Rand
Corporation
Team of experts prepare individual
estimates.
Benefits
Build a complete task list or work breakdown structure for major activities.Consensus approach helps eliminate bias in estimates.Eliminate hidden agendas or divergent objectives for inexperienced estimators or influential individuals.Does not require historical data to prepare the estimates.
Straightforward and Repeatable process
Process
Planning
Project Manager selects a team and a moderatorTeam consists of 3-7 team membersRepresentation from all groups like development, testing etcModerator to be familiar with the Delphi processIdeal to have the Project Manager as a part of estimation teamProject Manager should not be the moderator as he will have stake in the outcome of the estimation
Kickoff Meeting
Explain the Delphi process
Read the vision and scope document or any
supporting documents [Pre-requisites]
Review the goals of the estimation session
Brainstorm and note down the assumptions
Generate the initial WBS
Decide upon the unit for estimation
Individual Estimation
Estimate the time required for each task
Add any additional tasks to the WBS
Add any missing assumptions
Estimation Meeting
Moderator shares the estimates so that estimators can see the range of estimatesIndividual estimates are not sharedTeam members revises estimates based on group discussionsEstimates are revised until no estimator wants to changes his/her estimates.Estimators agree that the estimates are acceptable.
Wide Band Delphi Example
There estimators A,B and C are told to prepare the time required to prepare test scenarios for a projectThe initial estimations provided were
A – 18 Hours B – 38 Hours C – 58 Hours
The moderator then Calculates average estimate as 38 hoursReturns this with their original estimates to
the estimators
Wide Band Delphi Example
The estimators then meet and discuss the estimates The initial estimations provided were
A – 31 Hours B – 32 Hours C – 33 Hours
The moderator then Calculates average estimate as 32 hoursAsks the estimators if they agree with this as
the estimate
Iterations in Estimations
Round 2 X X X
Round 1 X X X
10 20 30 40 50 60
Assemble Tasks & Review Results
Project Manager works with the team and collects the estimates from team membersCompiles the final WBS, estimations and assumptionsReviews the final estimates with the estimation team
Ground Rules
All estimation sessions must be performed individually with no group interaction Estimators must indicate factors affecting their estimatesEstimators will ignore holidays, vacations and other similar factors Anonymity must be observed during the whole estimation process Estimation sessions should have a predefined time limit
Assumptions
Assume that one person will perform all
tasks
Assume all tasks will be performed
sequentially
Assume that you can devote
uninterrupted time to each task
About the Author George Ukkuru is working as a test manager UST
Global Trivandrum. He is having more than 10 years of experience in the field of software testing. He holds various certifications like PMP,CAPM,CSTE etc. He can be reached at [email protected]