Introduction

This technical description of Capabilities describes the purpose of Capabilities and their relationship to other PLCS components.

Capabilities provide guidance on how the IS0 1030-239 PLCS information model and associated Templates should be used. They correspond to the "chapters" of a notional PLCS usage guide within which a set of Templates are documented, which are then reused by multiple DEXs as shown in Figure 1.

Figure 1 —  The usage of Capabilities and DEXs.

A description of how EXPRESS entities are used to represent a given concept (a specific "functionality" or "capability"). It provides guidance and rules on what Entities should be used to represent a given concept, how the entities should be related, and what Reference Data should be used. As well as general guidance, a set of Templates are documented within a Capability to provide precise specifications of which Entities should be instantiated to represent identified concepts.

The concepts represented in the Capabilities are generic business level concepts (such as a "part" or an "approval") whose meaning is agreed within the PLCS OASIS community and is common to most applications of PLCS but which are not specific to a particular industrial domain. The Capability description is both graphical and textual to facilitate human understanding and consists of a business overview and a detailed description of the usage of the information model Reference Data classes. Each Capability also documents a set of one or more "Templates". Each Template provides a precise, computer interpretable specification of which PLCS entities are required and how they should be populated.

See the Templates section for further details on Templates.

Examples of Capabilities in PLCS are:

• C001: assigning_identifiers (NB Capabilities are not documented in this release of the PLCS standard)
• C002: representing_parts (NB Capabilities are not documented in this release of the PLCS standard)
• C010: assigning_reference_data (NB Capabilities are not documented in this release of the PLCS standard)
• C036: assigning_date_time (NB Capabilities are not documented in this release of the PLCS standard)

The function, structure, and purpose of Capabilities

The structure of the Capability is as shown in Figure 2 and comprises:

• a subset of the information model that can be used to define a particular business term;
• a definition of the information model;
• usage guidance for the model;
• usage guidance for the Reference Data;
• a set of Templates.

Figure 2 —  Structure of a Capability.

In summary, Capabilities:

• ensure (through the Templates) a common interpretation of PLCS;
• avoid multiple dialects of PLCS;
• reduce the amount of guidance documentation for those wishing to use only parts of PLCS; and
• simplify instantiation of the PLCS data model.

Types of Capabilities

Most Capabilities belong to one of three basic types, with the type often reflected in Capability name. Namely:

• Representing - A full set of information required to describe and classify the target. This would always include the provision for referencing the target;
• Referencing - Enabling a DEX to identify a target without the need to send the complete representation. This would always include the identification of the target;
• 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.)

Documentation of Capabilities

Each Capability is identified within the DEXlib repository by a number, an identifier and a name, e.g.

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

These are assigned to the Capability in the initial development process.

Each Capability contains:

• 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; and
• a set of one or more Templates.