ISBN : 978-81-963532-2-3 (E-Book) ExpertJudgmentTechnique Expert judgment is one of the most widely used estimation techniques. In this approach,an expert makes an educated guess of the problem size after analyzing the problemthoroughly.Usually,theexpertestimatesthecostofthedifferentcomponents(i.e.modu les or subsystems) of the system and then combines them to arrive at the overallestimate. However, this technique is subject to human errors and individual bias. Also, itis possible that the expert may overlook some factors inadvertently. Further, an expertmaking an estimate may not have experience and knowledge of all aspects of a project.For example, he may be conversant with the database and user interface parts but may notbeveryknowledgeableabout thecomputer communication part. A more refined form of expert judgment is the estimation made by group of experts.Estimation by a group of experts minimizes factors such as individual oversight, lack offamiliarity with a particular aspect of a project, personal bias, and the desire to wincontractthroughoverlyoptimisticestimates.However,theestimatemadebyagroupof experts may still exhibit bias on issues where the entire group of experts may be biaseddue to reasons such as political considerations. Also, the decision made by the group maybedominated byoverlyassertivemembers. DelphiCostEstimation Delphi cost estimation approach tries to overcome some of the shortcomings of the expertjudgment approach. Delphi estimation is carried out by a team comprising of a group ofexpertsandacoordinator.Inthisapproach,thecoordinatorprovideseachestimatorwithacopy ofthesoftwarerequirementsspecification(SRS)documentandaformforrecording his cost estimate. Estimators complete their individual estimates anonymouslyand submit to the coordinator. In their estimates, the estimators mention any unusualcharacteristicoftheproductwhichhasinfluencedhisestimation.Thecoordinatorprepar es and distributes the summary of the responses of all the estimators, and includesanyunusualrationalenotedbyanyoftheestimators.Basedonthissummary,theestimato rsre-estimate.Thisprocessisiteratedforseveralrounds.However,nodiscussion among the estimators is allowed during the entire estimation process. The ideabehindthisisthatifanydiscussionisallowedamongtheestimators,thenmanyestimators may easily get influenced by the rationale of an estimator who may be 153 Software Engineering Keerthana P, Manasa KN, Ganga D Bengal
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