This wiki is locked. Future workgroup activity and specification development must take place at
our new wiki
. For more information, see
this blog post about the new governance model
and
this post about changes to the website
.
TWiki
>
Main Web
>
PmHome
>
MetricsHome
>
MetricsWorkingDocuments
>
MetricsEMS10RestApi
>
MetricsEMS10RestApiDataModel
>
MetricsEmsScenario
(01 Oct 2010,
ArthurRyman
)
(raw view)
---+ ems:Scenario Domain entities: [[MetricsEmsProject][ems:Project]], [[MetricsEmsScenario][ems:Scenario]], [[MetricsEmsEstimate][ems:Estimate]], [[MetricsEmsBaseline][ems:Baseline]], [[MetricsEmsMeasurement][ems:Measurement]] %TOC% ---++ Description An ems:Scenario is an information resource that describes a project execution scenario. A scenario is one possible way of running a project. A scenario contains a set of assumptions about scope, resources, productivity, quality, and other metrics. Each assumption may be either a single measure, a fact table, or a work breakdown structure. Since assumptions involve quantities that may not be know precisely, they are described using probability distributions. While planning a project, it is useful to consider several alternate scenarios and compare their cost-benefit-risk trade-offs. For example, one scenario might be to reduce the requested scope to fit a given schedule, with a given staffing limit. Another scenario might be to deliver the complete requested scope as soon as possible using as much staff as needed. A manager might define the scenarios to be evaluated. However, if an estimator determines that none of the scenarios are viable, he might define alternate viable scenarios. Scenarios might be defined at the start of the project, or at any time during the course of the project when corrective action is required. Scenarios are the inputs to estimates. A manager adopts one scenario for the project by creating a new baseline that includes the scenario and its estimates. ---++ Properties An ems:Scenario resource contains the [[MetricsEMS10RestApiDataModel#Standard_Properties][Standard Properties]] and the following properties: | *Property* | *Range* | *Type* | *Occurrence* | *Edits* | *Description* | | dcterms:identifier | datatype | xsd:string | exactly-one | read-only | The short identifier for this scenario within its list. | | ems:scenarioList | resource | [[MetricsEmsScenarioList][ !ems:ScenarioList]] | exactly-one | read-only | The scenario list that this scenario belongs to. | | ems:project | resource | [[MetricsEmsProject][ems:Project]] | exactly-one | read-write | The project that this scenario applies to. | | ems:extendsScenario | resource | ems:Scenario | zero-or-one | read-write | The scenario that this scenario extends. | | ems:isActive | datatype | xsd:boolean | exactly-one | read-write | Is the scenario active? | | ems:assumes | local inline resource | [[MetricsEmsMeasureDistribution][ems:MeasureDistribution]] | zero-or-more | read-write | A measure distribution that this scenario assumes. | | ems:assumesTable | local inline resource | [[MetricsEmsFactDistributionTable][ems:FactDistributionTable]] | zero-or-more | read-write | A fact distribution table that this scenario assumes. | | ems:assumesWbs | local inline resource | [[MetricsEmsWorkBreakdownStructure][ems:WorkBreakdownStructure]] | zero-or-more | read-write | A work breakdown structure that this scenario assumes. | ---+++ dcterms:identifier See [[MetricsEMS10RestApiDataModel#dc_identifier][Domain Entities, dcterms:identifier]]. ---+++ ems:scenarioList See [[MetricsEMS10RestApiDataModel#ems_entity_List][Domain Entities, ems:{entity}List]]. ---+++ ems:project This property is a link to the ems:Project resource that this scenario applies to. Its value MUST be specified on creation and it SHOULD NOT normally be changed after that, other than to immediately correct an error since this change could invalidate any estimates that were previously based on the scenario. The referenced resource SHOULD belong to the same service as this result. This specification only defines behavior for when the referenced resource belongs to the same service as this resource. See [[MetricsEMS10RestApiDesign#Distributed_Computing][Distributed Computing]] for more information. ---+++ ems:extendsScenario A scenario MAY extend another scenario, refered to as the _base_ scenario, by adding new assumptions or refining assumptions present in the base scenario. All assumptions contained in this scenario override any corresponding assumptions in the base scenario. We refer to the base scenario as the _parent_ of this scenario. An _ancestor_ of a scenario is either its parent or an ancestor of its parent. In practice, an estimator may extend a given base scenario in order to record additional assumptions made in the process of estimation. The resulting estimate should refer to this extended scenario instead of the base scenario. This optional property links to an ems:Scenario resource that this scenario extends. Its value, if present, MUST be specified on creation and it SHOULD NOT normally be changed after that, other than to immediately correct an error since this change could invalidate any estimates that were previously based on the scenario. The referenced resource SHOULD belong to the same service as this resource. This specification only defines behavior for when the referenced resource belongs to the same service as this resource. See [[MetricsEMS10RestApiDesign#Distributed_Computing][Distributed Computing]] for more information. If this property is present then the ems:project resource MUST have the same value as the ems:project property of the base scenario. Note that an ems:Estmate resource MAY refer to an ems:Scenario resource that extends another ems:Scenario resource. If any ancestor scenario is modified after the estimate is created, then is may no longer be valid. The service MAY prevent scenarios from being modified after an estimate uses it either directly or indirectly using access control and policy enforcement mechanisms. The service SHOULD also maintain revision histories to the revisions in effect when the estimate was created can be determined. ---+++ ems:isActive This boolean property indicates whether the scenario is under active consideration as a potential way of running the project. A true value indicates to estimators that they should provide estimates for this scenario when requested. When a scenario has been rejected, this property should be set to false to avoid further estimation work. After negatively evaluating a scenario, a manager should set this value to false to indicate that is no longer under active consideration as a way to run the project. ---+++ ems:assumes This property gives an assumption for this scenario. A scenario may have zero or more assumptions. The object of this property is an inline [[MetricsEmsMeasureDistribution][ems:MeasureDistribution]] resource. An assumption is any condition or constraint that must be obeyed in the scenario, e.g. schedule, staffing, scope. Assumptions often involve imprecisely known quantities such as productivity or size. The uncertainty in assumptions is expressed by giving a probability distribution for the assumed quantities. ---+++ ems:assumesTable Like ems:assumes, except that the object of this property is an inline [[MetricsEmsFact Distribution Table][ems:FactDistributionTable]] resource. ---+++ ems:assumesWbs Like ems:assumes, except that the object of this property is an inline [[MetricsEmsWorkBreakdownStructure][ems:WorkBreakdownStructure]] resource. ---++ Examples * [[MetricsEMS10PrimerInitiatingSetup#Listing_of_ASAP_Scenario_Represe ][EMS 1.0 Primer, Listing of ASAP Scenario]] * [[MetricsEMS10PrimerInitiatingSetup?#Listing_of_Scenario_5721_Resourc][EMS 1.0 Primer, Listing of Scenario 5721]] * [[MetricsEMS10PrimerInitiatingInvestmentRisk#Listing_of_Scenario_with_Triangu][EMS 1.0 Primer, Listing of Scenario with Triangular Distribution]] ---++ Comments Add your comments here: %COMMENT%
E
dit
|
A
ttach
|
P
rint version
|
H
istory
: r14
<
r13
<
r12
<
r11
<
r10
|
B
acklinks
|
V
iew topic
|
Ra
w
edit
|
M
ore topic actions
Topic revision: r14 - 01 Oct 2010 - 20:15:30 -
ArthurRyman
Main
Main Web
Create New Topic
Index
Search
Changes
Notifications
RSS Feed
Statistics
Preferences
Webs
Main
Sandbox
TWiki
Български
Cesky
Dansk
Deutsch
English
Español
Français
Italiano
日本語
Nederlands
Polski
Português
Русский
Svenska
简体中文
簡體中文
Copyright � by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Contributions are governed by our
Terms of Use
Ideas, requests, problems regarding this site?
Send feedback