RDS/WIP: An Introduction

This page is written to hopefully introduce the uninitiated to what the IDS-ADI team call the RDS/WIP.

What the RDS/WIP Stands for

The RDS/WIP stands for "Reference Data System" and "Working, in Progress"*, essentially combining the PCA IDS project's original reference data library system with the FIATECH ADI project's reference data library system, and using much of the ground work laid out in the drafts of ISO 15926 part 7.

What the RDS/WIP is

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)

Why Reference Data is Needed

ISO 15926's brief is to act as an interoperability framework for engineering data.

The Same Data Suited to Many Different Tasks

The standard needs to accommodate typical activities related to that data. The breadth of these activities is very wide - the data must pass through design, procurement, installation, operations, maintenance and planning activities.

As the data passes between systems used in these different activities, it must retain its fidelity and precision, and still be meaningful and task-oriented to the users. That is to say, that the best way to present data for one task might be quite different to the best way for another task, and a standard must accommodate this.

Making Data Precise and Neutral

ISO 15926 data is built from a rigid, ontological-style data model - this comprises many small pieces of information used to build up the complex relationships of real-life data.

Using very small pieces of information (what we call "binary relationships") allows extremely precise expressions, but those small pieces of information are not intelligible to users of the data - information systems are typically built at a much coarser level that reflect the way their users think of the data. The way a user thinks of their data is usually task-specific, not a neutral form of the data suitable for other tasks.

Making Data Concise and Meaningful

So this brings any interoperability standard to the problem of how to make the data neutral, but at the same time concise and meaningful. The approach that ISO 15926 takes is to find the repeating patterns of small pieces of information that are useful in many contexts, identify how those clusters relate to the rest of the data, and to wrap up each cluster into a larger unit.

Once repeating patterns have been identified and named, they can be re-used without having to remember how they look "inside" - a user can just take the named pattern and use that, plugging values into the external relations only.

This process can be repeated, taking the larger patterns of identified patterns and building up even bigger repeating chunks. By repeating this process we ultimately reach data at the level of meaning that humans are used to dealing with, such as "the average energy use of the pump identified by tag TF1034 in this installation is 4kW".

Making Useful Patterns of Data into Reference Data

It is much better if multiple parties can re-use the general pattern "the average energy use of <installed-equipment-specification> is <energy-value>" to exchange data, rather having to pass around many tiny pieces of information that fit that pattern.

This is the reason why the RDS/WIP exists, to register and define these patterns, so that people from different companies can exchange concise, meaningful data, without having to understand the complex details of how it is made up.

It is analagous to saying "this is a blue sapphire" versus saying something like "this is an occlusion free crystal in a trigonal Bravais lattice, made of identical molecules, each comprised of a compound of two aluminium atoms in a valence bond with three oxygen atoms; with an admixture of trace iron contaminants". The former is how humans communicate to each other, the latter describes some aspects of what it actually is.

The Problem of Scale

While we might have only a couple of hundred basic relationships that we can express down at the very "atomic" level of the data, that is to say, we might have only a small number of kinds of information at the deepest level of the data, at the next level up we have many thousands, and as we reach the highest level, where the patterns hide many tiny relationships, we end up having at least tens of thousands of these patterns, possibly hundreds of thousands depending on how far the standard extends (into what industries and occupational contexts).

To produce hundreds of thousands of complex, rigorous definitions that require input from many different domains of expertise, is a massive task beyond that of any single organization. So the solution is to involve multiple organizations, and solicit each of them to create those definitions that are useful to them and to collaborate on definitions that they can usefully share.

The RDS/WIP is the Collaboration Platform

The IDS-ADI group is the umbrella group that organizations can join to collaborate on defining these useful patterns, in an environment that provides support in terms of ontological and modeling expertise, training, methodology, procedures and finally, a technical platform to collaborate and publish definitions: the RDS/WIP.

The RDS/WIP is the technical platform for the collaboration work that IDS-ADI facilitates:

  • it is used to publish a representation of concepts from ISO 15926 in a standard format;
  • it will allow accredited modelers to publish definitions for others to use;
  • it will allow definitions to be augmented, extended and reused;
  • it will provide a space for other standards to be published in a similar format and harmonized with ISO 15926;
  • it allows real-time human and machine query of all of the accumulated definitions.

How Contribution and Standardization Will Work

There are several basic types of contribution that can be made to the RDS/WIP:

  • ISO 15926 core concepts
  • ISO 15926 core reference data
  • ISO 15926 contributed reference data
  • definitions in other standards

The procedures for publishing each contribution is a little different. Please note that these procedures are not "etched in stone" - they are evolving and may change over time. These are just an indication of how IDS-ADI currently sees it working.

ISO 15926 Standard

The current process is that the IDS-ADI group provides funding and in-kind contributions from members of its parent bodies, PCA and FIATECH in order to define ISO 15926 core concepts for the RDS/WIP, according to the latest collective thought around ISO 15926 part 7 OWL/RDF representation.

Members of FIATECH and PCA are very welcome to become a part of this process and help IDS-ADI make the best possible OWL/RDF representation of ISO 15926.

ISO 15926 Core Reference Data

The core reference data is currently being contributed from existing systems, such as the original PCA RDS system. The basis of this set was published as ISO 15926 part 4 and it is anticipated that the core reference data will continue to expand, with ISO sanctioned status.

Future core reference data is expected to come through the WIP initially as "contributed reference data" (see below), and be "elevated" to various levels of standard status as they are validated.

The validation process, at least for ISO status, is defined in part 6 of the standard [check]. The validation process is likely to be performed by members of the IDS-ADI group initially. Informally, these personnel have been referred to as "black belt modelers" [terminology subject to change].

ISO 15926 Contributed Reference Data

Some of the entries in the existing RDS system, along with pending contributions from software vendors and EPCs, will enter the system as contributed reference data. That is to say, while it is published in the system, it has no warranty applied to it by IDS-ADI or ISO.

Future submissions to the WIP are all intended to start as contributed reference data. Any person that IDS-ADI entrusts to enter data into the system will be provided with authentication credentials and access to the system.

Currently, IDS-ADI's plans are to accredit individuals after participating in a training program. Those who will participate in and pass the training program have been informally designated as "yellow belt modelers" [again, terminology subject to change].

Once a reference data contribution has been submitted, it may be optionally marked for review and validation - for eventual elevation to core reference data status. Anyone can add this mark, not just the original submitter.

Non-ISO 15926 Definitions

The future RDS/WIP system will be able to accommodate definitions made completely outside of ISO 15926 - definitions in any kind of RDF/XML will be allowed, so, as long as they are published at an endpoint not used for ISO 15926 proper.

The use of the RDS/WIP system for publishing non-ISO 15926 standards in RDF will be evaluated on a case by case basis - no decision has been made whether to require any sort of accreditation or anything like that - its likely that once a space has been set up for publishing that data, managing it will be left up to the owners of those other standards.

This approach could also be used for ISO 15926 representations of vendor data, should vendors wish to publish their own ISO 15926 definitions on the same system (they could alternatively use their own system too).

What the RDS/WIP Is Built of

The RDS/WIP uses semantic web technology (see: OWL, RDF and SPARQL) over the top of conventional web technology such as HTTP to provide machine-oriented access to the stored definitions. A conventional HTML presentation is used to provide a human-oriented interface to the same system.

* The ADI term,"Working, in Progress" is a reference to the use of the title initially coined by Joyce for "Finnegan's Wake": "Work in Progress" - commonly used since to indicate an incomplete or unfinished thing. WIP in this case can contain many usable things and complete things, but as a whole it will never be complete and will always be being added to, and thus is both "working" and "in progress".

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