Getting to know ISO 15926
By Brian Eastwood
Category Tags: Building Information Modeling
ISO 15926 is an International Organization for Standardization (ISO) standard for exchanging data among the computer systems that are used in the design, construction and maintenance of oil and gas facilities. The standard aims to reduce data errors and, in automating the process of exchanging data, to reduce significantly the amount of time necessary to transmit data. In this article we provide an introduction to ISO 15926 that explains how it is structured, how it is being used and where additional information can be found.
An overview of ISO 15926
The official title for the ISO 15926 standard is "Industrial automation systems and integration -- Integration of life-cycle data for process plants including oil and gas production facilities." (There are nine parts to ISO 15926; these will be discussed below.)
The standard has been around, in various forms, for more than a decade, but in 2006 an effort began in earnest to advance its completion. It started with two groups -- FIATECH and the POSC Caesar Association -- and their respective Advancing the Development of ISO 15926 (ADI) and Intelligent Data Sets (IDS) projects; taken together, the IDS-ADI project acts as a custodian of sorts for ISO 15926.
As Ian Glendinning, principal consultant for information risk management at DNV, put it during a presentation on the first day of the 2008 FIATECH Member's Meeting, ISO 15926 is about establishing a sound methodology for sharing common reference data.
The POSC Caesar Association's lengthy primer for ISO 15926 cites the example of designing, installing and commissioning a process instrument. Throughout this process, information is retyped at least half a dozen times, then printed out and/or saved onto a CD. The process can take months, and with all that data re-entry, mistakes are hard to avoid.
"What we need is a way for each participant's software to be able to communicate complex information to the other participants without having to know in advance things like database structure or format," the primer's authors state.
Through ISO 15926, stakeholders use facades to exchange this complex information. This façade has been compared to the Babel Fish of Hitchhiker's Guide to the Galaxy fame; it has also been compared to HTML, Esperanto on a cell phone and a GUI for machines. It can also be thought of as an SOA implementation with a standard interface.
Metaphors aside, ISO 15926 is poised to change the way that everyone involved in a project shares information. "It is difficult to overestimate the value of being able to exchange information with anyone, more or less instantaneously, without fear of transcription error, and while maintaining the precise meaning of all the terms, even though you know nothing at all about your partner's database configuration," the primer's authors say in the How ISO 15926 Will Make Your Life Easier section.
"When information is transferred correctly," they continue, "the quality and reliability of your end product increase. When you know for sure that the information has been transferred correctly you can move faster because you do not have to check for errors." And when you move faster, you save time and money.
What ISO 15926 looks like
The ISO 15926 standard consists of nine main parts, plus a set of abstract compliance test methods that, according to POSC-Caesar, are not yet a part of ISO15926 but reflect an industry-wide consensus on what compliance with the standard entails:
- Preamble
- Data Model
- Geometry, or reference data, which is then "harmonized" with parts 4, 5 and 7
- Initial reference data
- Registration and maintenance of reference data
- Scope and methodology for developing additional reference data
- Template implementation model; this was formerly referred to as "Implementation methods" and has since been broken into Parts 7-10
- OWL and RDF implementation schema for the semantic Web (OWL stands for Web Ontology Language, while RDF is Resource Description Framework)
- Façade implementation technology
If the reference data contained within ISO 15926 were to be diagrammed, it would resemble a pyramid with four sections.
- The top of the pyramid consists of core data that defines relationships among physical things.
- The next level contains core content classes, which are loosely defined common terms. This class, for example, would define the concept of a pipe. (If you remember Plato's Theory of Forms from your college philosophy class, then the Form of a pipe would be defined here. If you don't remember, never mind.) Initially, Glendinning said, these core content classes were too narrowly defined, as users were adding, say, a cooling water pump as opposed to simply a pump.
- The next level is made of standard classes. These physical objects, activities, property classes, templates and object information models have been standardized already; users are able to "hook into" these standards or add standards if they are not already there. This class, for example, would define a 2" pipe. This is also where ANSI and API standards fit in, Glendinning pointed out.
- Finally, the bottom level consists of proprietary classes. These, too, are physical objects, activities, property classes, templates and object information models, only here they represent vendor products and catalog items -- one company's 2" pipe, for example.
Overlaying the second and third sections of the pyramid is the RDL/WIP, which is an online Reference Data Library database managed by the RDS/WIP system for publishing ISO 15926 definitions. (RDS stands for Reference Data System, while WIP stands for Work in Progress.)
What ISO 15926 is not meant to be is a repository for common reference data. This means that the standard itself is not going to identify what attributes belong to a particular element (say, a centrifugal pump).
The absence of this information is not necessarily a fault of the standard, noted Robin Benjamins, engineering automation manager at Bechtel. Rather, he said, it shows that the key to ISO 15926 is its methodology and standardizing approach and not its content, since the content is going to differ based on one's business needs. (Along those lines, users should enter their requirements and other relevant information if it is not there, Benjamins said.)
Business use cases for ISO 15926
The business case for ISO 15926 is multifaceted -- after all, EPC firms, facility owner/operators (hereafter OOs) and software vendors all need to buy into the standard. At the FIATECH Member's Meeting, companies in all three industries offered their thoughts on what they hope to get out of ISO 15926.
For EPCs such as Bechtel, ISO 15926 improves efficiency and reduces data deduplication. For OOs such as nuclear power plants, data interoperability reduces the costs of expansion -- and, given global energy needs, what power plant wouldn't be looking to expand? Finally, for software vendors the standard presents a way to make life easier for customers, existing and potential.
Phil Robins, development manager of project engineering and lifecycle tools at AVEVA, pointed out that a number of ISO 15926 implementations are already in place. These implementations involve the exchange of P&ID information, 3-D model information and both of the above. (P&ID stands for Piping or Process and Instrumentation Diagram.)
So far, the EPCs and OOs involved in these implementations have, through the movement of documents between CAD software tools, clarified the relationship between key components within designs, thereby maintaining the designs' engineering integrity, Robins said. Additionally, the firms now have an easier time performing P&ID-to-3-D comparisons of attributes such as topology and outputting key data to Excel, he added. (The Existing Usage of ISO 15926 section of POSC Caesar's primer is, for the moment, a stub, though three use cases have been listed there.)
Another way to look at the business case for ISO 15926 is to consider the alternative -- that is, eschewing interoperability for a rigid data model. The danger here, Benjamins said, is that, by the time data is adhered to the data model, there's a good chance that the data model will have changed. The consequences, he added, can run into the billions, as the Airbus A380 cost overruns and A380 delivery delays proved.
So what's next?
ISO 15926 is a work in progress. At the FIATECH Member's Meeting, the IDS-ADI project presented its master plan for 2009. Areas of that plan related to ISO 15926 include implementing 2-D and 3-D geometry into templates, consolidating of the template implementation models in Part 7 and prototyping security systems for the façade implementation technology in Part 9.
As work on ISO 15926 continues, it is worth keeping in mind how AEC firms, facility owners and operators and software vendors all stand to benefit from the standard. Referring again to the POSC Caesar primer's How ISO 15926 Will Make Your Life Easier page, it is said,
The value of ISO 15926 stems entirely from the benefit of being able to transfer information directly from one software application to another, without needing prior knowledge of either application, automatically and while maintaining the meaning of all the data values transferred.
The following resources, some of which have been referred to above, offer additional information about the standard.
- Introduction to ISO 15926 (POSC-Caesar Association)
- ISO 15926 Standard Structure (POSC-Caesar Association)
- Accelerating Deployment of ISO 15926 (FIATECH / ADI)
- RDS / WIP Project (POSC-Caesar Association)