About PLCS Capabilities

The Capabilities are the building blocks from which a DEX is constructed. Capabilities perform a similar function to Modules within STEPmod although there is not a one-to-one correspondance. They are used to accelerate DEX development and to avoid different interpretations of equivalent concepts in different DEXs.

The structure of the capability is as shown in Figure 1 and comprises:

• an introduction, explaining the nature and purpose of the capability.
• a business overview.
• a description of the information model used by the capability, with examples of its use.
• a full specification of the information model used by the capability, derived from the relevant AP239 Implementation Module.

A capability is a portion of the PLCS data model that is reused in instantiations of the information model. A Capability is independent of business context and domain of the instantiations. Reusability is solely based on the structural similarity of the instantiations; a Capability consists of a fixed set of entities, relationships, and internal, fixed-value attributes. A Capability may be regarded as a macro-entity with a set of parameters. Its purpose is not in data modelling, but in describing typical instantiations of a portion of a data model.

Why Capabilities:

• To ensure a common interpretation of PLCS.
• To avoid multiple dialects of PLCS.
• To reduce the amount of documentation for the PLCS usage guide.
• To simplify instantiation of the PLCS data model.

Three types of Capabilities

A capability can be identified as one of three types/families (and then there is the 'messaging' cability). They are named,

• Representing - A full data set describing and classifying the target This would always include the provision of a referencing function.
• Referencing - Enabling a DEX to identify a target without the need to send the complete representation. This would always include an identification function.
• Assigning - The ability to attach routine pieces of additional information, as required, to elements within a representation. (The use of "Assigning" as the introductory verb to the capability is not always appropriate and is therefore not mandated.)

Then there is also the concept of "Core Capabillities"...

What is a Capability

A capability identifies a subset of the information model that can be used to define a particular business term. For example rerpesenting a part.

Each capability provides a definition of the information model and usage guidance on the model.

Each capability defines a set of templates. These are patterns that define precisely which entities are to be instantiated in order to represent a given business term. A template may use other templates in its definition.

Identification of a Capability

Each Capability is identified by a number, an identifier and a name, e.g.

• number — C001
• identifier — assigning_identifiers
• name — Assigning Identifiers