0021 Collections¶

Collections provide a general mechanism for grouping entities together. A collection may be maintained manually, or via an automated process (ie a "smart collection").

The membership of a collection is established via a CollectionMembership relationship, which has attributes that allow the rationale and the confidence of the membership to be established. A Referenceable entity can be a member of none, one or many collections.

Since a collection is itself :wq a Referenceable entity, collections can be organized into hierarchies - like a directory structure on the filesystem.

Collection entity¶

The Collection entity describes a parent node for collecting related elements together. It inherits from Referenceable. There are no additional attributes for a collection, beyond the standard attributes for Referenceable.

Collection Subtypes¶

The collection type is generically useful and there are many subtypes that describe specialist collections in addition to RootCollection and CollectionFolder show in this model.

• Agreement described a collection of elements that are part of an agreement.
• BusinessCapability described a collection of capabilities needed to operate the business of an organization.
• ConceptModel described a collection of modelled concepts.
• DataDictionary described a collection of commonly used data field definitions.
• DataSpec described a collection of data fields and related definitions that describe the data required.
• DesignModel described a collection of modelled elements.
• DigitalProductCatalog described a collection of digital products that make up a product catalog.
• DigitalProduct described a collection of related assets that make up a digital product.
• DigitalProductFamily described a collection of digital products that can be subscribed to as if they were a single product.
• DigitalSubscription is a special type of agreement relating to subscriptions to digital resources.
• EventSet described a collection of event schema definitions.
• Glossary described a collection of GlossaryTerms.
• InformationSupplyChain described a collection of components performing an important data flow.
• SolutionBlueprint described a collection of components performing a solution.

RootCollection entity¶

The RootCollection entity indicates that the collection is used to provide the starting node for an independent hierarchy of collections. For example, this could be a collection hierarchy that organizes digital products.

CollectionFolder entity¶

The CollectionFolder entity is a collection that is used to organize subsets of metadata elements within a larger collection. It means the collection can be treated as if it where a folder.

The example below shows part of a collection hierarchy representing a digital product catalog. The collections are shown in green and the assets that provide the content for the digital product are shown in yellow.

The RootCollection collection at the root of the collection hierarchy is called "Product Catalog Collection". Its membership consists of CollectionFolder collections. The leaf node DigitalProduct collections have the data assets as their members.

Collection classifications¶

The classifications associated with Collection allow it to be specialized for particular uses. They help when searching for collections for specific uses.

• HomeCollection means the collection is the top-level node in a collection hierarchy anchored to a specific Referenceable. The members of this collection may or may not be collections.
• Namespace means the collection is a set of elements that are organized by namespace (for example, a collection of processes, or schema).
• ResultsSet means the collection is a set of related results.
• RecentAccess means the collection is a set of elements that have been recently accesses by a user.
• WorkItemList means the collection is a set of elements that have been recently accesses by a user.
• EventSet for a collection of related event schemas.

HomeCollection classification¶

The HomeCollection classification indicates that the collection is used to provide the starting node for a hierarchy of collections.

Namespace classification¶

The Namespace classification indicates that the collection is a set of elements that are organized by namespace.

ResultsSet classification¶

The ResultsSet classification indicates that the collection is a set of elements that are the results from a specific request or query.

RecentAccess classification¶

The RecentAccess classification indicates that the collection is a set of elements that have been accessed recently.

WorkItemList classification¶

The WorkItemList classification indicates that the collection is organizing a set of elements (typically ToDos, or Tasks).

CollectionMembership relationship¶

The CollectionMembership relationship is used to link a Referenceable entity to a Collection entity to indicate that it is a member of the collection.

The Collection entity inherits from Referenceable so a collection can be a member of other collections. For example, it is possible to create a nested set of folders for assets.

The attributes for the CollectionMembership relationship establish the level of trust to give to a member's right to be part of the collection:

• The membershipRationale attribute describes why the member is part of the collection.
• The expression attribute indicates the expression used to decide on the membership. This is typically set up by automated processes to identify the rule they used to determine the membership.
• The confidence attribute indicates how confident that the membership is correct.
• The createdBy attribute is the identifier of the process or person that created (curated) the relationship. This is useful for identifying the instance of a process that created the membership relationship or the curator if they are different from the steward.
• The source attribute describes the source of information that identified this membership.
• The steward attribute identifies the person that is accountable for the correctness of this membership relationship.
• The stewardTypeName attribute identifies the type of element (such as UserIdentity, Person, PersonRole) that is responsible for the correctness of this relationship.
• The stewardPropertyName attribute identifies the property (such as guid or qualifiedName) used to identify the steward.
• The notes attribute enables the steward to add additional information about this relationship.
• The membershipStatus attribute indicates the status of the member in the collection. It is a MembershipStatus value.
• The userDefinedStatus provides a status value when status=OTHER.

MembershipStatus enumeration¶

The values for the MembershipStatus enumeration are:

• Unknown - The membership origin is unknown. This is the default value.
• Discovered - The membership was discovered by an automated process.
• Proposed - The membership was proposed by an expert curator. The curator uses their expertise to create the membership. They may or may not be the steward who is ultimately accountable for the correctness of the membership.
• Imported - The membership was imported from another metadata system.
• Validated - The membership created by an automated process has been validated and approved by an expert curator. Again, the curator may or may not be the steward.
• Deprecated - The membership should no longer be used.
• Obsolete - The membership must no longer be used.
• Other - Another membership status that is set up in the userDefinedStatus attribute.

They can be used to support a simple stewardship workflow. For example, consider an engine action that scans through the assets examining each one's Retention classification. If the values in the classification indicate that the resource that it represents should be archived, it may link the asset into a collection.

The status value could be Discovered in each CollectionMembership relationship. Once the collection is complete, the governance action could trigger a request to a steward to verify the list. The steward could update the CollectionMembership status to either:

• Validated - The resource should be archived.
• Obsolete - The resource should be retained.

Once the review is complete, another governance action would drive the archive process for all resources indicated by the CollectionMembership relationships with Validated status.

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