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ems:Estimate

Domain entities: ems:Project, ems:Scenario, ems:Estimate, ems:Baseline, ems:Measurement

Description

An ems:Estimate resource is a set of predictions based on the assumptions in some scenario. Each prediction may be either a single measure, a fact table, or a work breakdown structure. Since estimates involve uncertainty, they are descributed using probability distributions.

Properties

An ems:Estimate resource contains the Standard Properties and the following properties:

Property Range Type Occurrence Edits Description
dcterms:identifier datatype xsd:string exactly-one read-only An identifier that is unique within the ems:EstimateList resource.
ems:estimateList resource ems:EstimateList exactly-one read-only The list that this resource is a member of.
ems:scenario resource ems:Scenario exactly-one read-write The ems:Scenario resource that this resource is an estimate for.
ems:predicts local inline resource ems:MeasureDistribution zero-or-more read-write A measure distribution predicted by this estimate.
ems:predictsTable local inline resource ems:FactDistributionTable zero-or-more read-write A fact distribution table predicted by the estimate.
ems:predictsWbs local inline resource ems:WorkBreakdownStructure zero-or-more read-write A WBS predicted by this estimate.

dcterms:identifier

See Domain Entities, dcterms:identifier.

ems:estimateList

See Domain Entities, ems:{entity}List.

ems:scenario

The ems:Scenario resource that defines the assumptions for this estimate.

Note that the ems:Scenario resource MAY be modified after the ems:Estimate resource is created, and that some assumptions could have changed therby invalidating the estimate. An EMS 1.0 service implementation MAY prevent this type of modification using implementation-dependent access control and policy enforcement mechanisms, e.g. the service MAY prevent a scenario resource from being modifed after any estimate uses it. If the service permits ongoing modification of the scenario resource then it SHOULD maintain the revision history of each resource so that the revision of the scenario resource that was in effect when the estimate was created can be determined.

ems:predicts

This property gives a prediction for this estimate. An estimate may have zero or more predictions. The object of this property is an inline ems:MeasureDistribution resource.

A prediction is any quantity that may be measured for the project, e.g. schedule, staffing, scope. Predictions often involve imprecisely known quantities such as effort or quality. The uncertainty in predictions is expressed by giving a probability distribution for the predicted quantities.

ems:predictsTable

Like ems:predicts, except that the object of this property is an inline ems:FactDistributionTable resource.

ems:predictsWbs

Like ems:predicts, except that the object of this property is an inline ems:WorkBreakdownStructure resource.

Examples

Comments

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Topic revision: r8 - 25 Nov 2010 - 20:01:51 - ArthurRyman
 
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