5.3.1 Feature Level

A feature can be any top-level business object required by a business process, such as the individual data objects or organization data objects described above or listed in Table 3.4-1 . The creation of a feature is a declaration that this is a business object that will be further studied and developed over a span of time. As such, it must be uniquely identified and we must be able to access all data and information related to it, including future interpretations of it, future representations of those interpretations, and the properties attached to the representation. A feature may be:

• An individual data object, such as:

• a geologic feature (e.g., a geologic unit or a geologic boundary)
• a technical feature (e.g., a wellbore or seismic data).

• Or a complex business object of interest on which users will study, collaborate and further develop using various software applications:

• an organization (e.g., an earth model, a structural organization, a stratigraphic organization, a reservoir, a seal, a source rock, etc.)

When beginning a series of data exchanges between software packages (or applications), the user must determine a reference feature data object that will be the entry point and the "pivot location" for identifying related interpretations and representations.

The role of the feature is to ensure a unique reference, which is why each feature has a UUID and metadata. The attached metadata (a citation element) reports the circumstances of the creation of this feature.

At the beginning of an exchange between software packages, to avoid redundancy and to ensure reliable management of the data object, the "reader" software must verify whether or not it has already imported this specific feature data object. If it has already imported the feature, it must not import it again. Instead, it should retrieve the data it has stored on that feature and determine if the new data being exchanged contains any updates or new information.

This specific feature data object must not be modified; rather, all changes to the data object are made at the interpretation, representation or property level. As data objects are exchanged back and forth among software applications, each package updates metadata (appropriately, based on the changes it made) for interpretations, representations, and properties.

For more information on features and interpretations in the context of an earth model, see 9 Earth Model .