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  1. AEX (Automating Equipment Information Exchange)
  2. RDF
    1. Metadata
    2. Data Model
    3. Abstraction
    4. RDF
    5. Subject-Predicate-Object
    6. Uniform Resource Identifier
    7. More Information about RDF
  3. RDL
    1. RDS/WIP
  4. IDS Task 120
    1. Some Definitions

AEX (Automating Equipment Information Exchange)

The Automating Equipment Information Exchange (AEX) project is developing, demonstrating and deploying eXtensible Markup Language (XML) specifications to automate information exchange for the design, procurement, delivery, operation and maintenance of engineered equipment.

AEX – The natural collaboration between AEX and IDS-ADI is via the Matrix/SIG’s teams.


Resource Description Framework

If you dig deeper under the hood of ISO 15926 you will soon run into this term because it is the means of storing the Part 4 definitions.

Wikipedia says that Resource Description Framework is a set of specifications originally designed as a metadata data model. But if you are like the author, this doesn't help at all. So we will deconstruct the defintion:


  • Metatdata is data about data. For instance, one piece of metadata about the ISO 15926 Primer is that it was written on the POSC Caesar's wiki website.

Data Model

  • A data model is an an abstract model that describes how data is represented and accessed.


  • Abstraction is a process of generalizing about something to reduce the information content about an object to only those attributes you are interested in. A typical abstraction is the answer "12345-Glover Crescent" to the question "Where do you live?" You might live in a beautiful split level house with a wonderful view of the ocean framed by huge 100 year old pine trees but your questioner only wants to know where to have a package delivered. (Or conversly, yours could be a very ordinary house on a very ordinary road, but the city just wants to know where to send the bulldozer.)


Putting it all together, then, RDF is:

  • instructions on how to represent
  • just the bits of data you are interested in
  • that describes certain other bits of data
  • then access it easily

(Whew! I bet you thought it was going to be difficult!)

In particular, RDF makes statements about things, which it calls Resources, in the form of subject-predicate-object expressions known as Triple Stores.


"The ISO 15926 Primer was written on the POSC/Caeser wiki" might be stored in the RDF as the triple:

  • the subject ISO 15926 Primer
  • the predicate was written on
  • the object POSC/Caeser wiki

The subject-predicate-object may be explicitly named, as in the example, or they could be a URI, a Uniform Resorce Indicator.

Uniform Resource Identifier

A Uniform Resource Identifier is more-or-less just a website for a piece of information. This allows the the same resource to be referenced by many sources reliably. So instead of writing the Subject-Predicate-Object triple as above, it could be rendered as:

And in fact we could carry this further by defining somewhere on the Internet the exact meaning of the phrase was written on, and put its URI in the predicate.

More Information about RDF

A good place to start if you want to know more about RDF is the RDF Primer written by the W3C. Be warned, it is not for the feint of heart.


Resource Description Library


The RDS/WIP is several things:

  • a library of reference data for ISO 15926
  • a means of publishing core ISO 15926 definitions
  • a platform for developing new ISO 15926 definitions
  • a workspace for harmonizing other standards with ISO 15926 (or each other)

IDS Task 120

How to use templates

Some Definitions

Semantic versus syntactic-
Semantic precision-
Semantic fidelity-

We will introduce several new concepts that are fundamental principles of interoperability and integration. They directly relate to the cost of interoperability and integration. Understanding these is the key to reducing cost.

Conservation of complexityYou can't get away from complexity. You can move it from one place to another, but it will always be there somewhere
AbstractionRepresenting real objects in a general, abstract form
EncapsulationHiding complexity from users who really don't want to know any more
Semantic precision-

[Input requested: I'm looking for a good place to talk about these terms. GPR]

Semantic versus syntactic-
Semantic fidelity-



For an extremely detailed Glossary, see STEPDEX: Glossary of Data Management Terms

Glossary of STEP and PDM related terms



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