The abstract concept of a "Phase". An ObsProject will accumulate data pertaining to different "Phases" of the Project, Phase I (Proposal preparation) and Phase II (Observing Program Preparation) are the most obvious, but other phases may be identified. In particular the reviewing comments and decisions are captured in a "Phase".
The characteristic common to all Phases is that they contain an ObsPlan. For Phase I this is the planned program at that time. For Phase II this is the approved part of the program and represents what will actually be observed. The full concept for other phases is not defined, but could be developed.

General Info
Name	ObsPhase
Owner	obsproject
Visibility	public
Is Active	false
Is Abstract	true

Relations
Name	Type	Begins	Ends
unnamed	Generalization	ObsProposal	ObsPhase
unnamed	Association	ObsPhase	ObsUnitSet
unnamed	Association	ObsPhase	AbstractScienceGoal
unnamed	Generalization	ObsReview	ObsPhase
unnamed	Generalization	ObsProgram	ObsPhase

Attributes
Name	Type	Classifier	Default Value
ObsPlan	ObsUnitSet	ObsPhase
unnamed	AbstractScienceGoal	ObsPhase