During the life cycle of a plant, from conceptual design to demolition, many parties create and use data about that plant or components thereof.
They use many different software packages for that, and each package stores that data in its own, proprietary, format. Because of this, data exchange, integration or hand-over has become a difficult and costly undertaking.
This can be compared with the difficulties in communication between people who speak different languages. In that case a solution is that a common language is used, such as English, Spanish, French, Russian, or Mandarin Chinese.
A similar solution can be found for information exchange between systems with different representations of that information. That solution is to use a common representation of information.
There are many such common representation methods on the market, and they have in common that they cover only a part of the information spectrum related to a plant.
Since the late eighties work has been done by an international team of modellers in developing a data model that would cover all the lifecycle information of a plant, its components, and its streams. That data model has been standardized in ISO 15926.
The model is a generic and fine-grained one, that allows for explicit modelling of individual data elements, and then grouping those in files or documents. Since no two documents or system files contain exactly the same data, this fine granularity allows for exchange of only the data that they have in common.
As every engineer knows it is of utmost importance that there is no confusion about the exact meaning of exchanged data. Unfortunately documents and data tables often lack that precision. Much of the information content is "implicit", i.e. it is not stated explicitly, but implied, and only understandable for insiders. In most cases this presents no problems, but in a globalizing economy, where parties from different parts of the globe cooperate, the risks of misunderstanding increase.
Generic data models require reference data libraries to specify the exact information content. ISO 15926 contains such a library, with clear definitions of all the terms used.
Today a natural carrier for information exchange is the Internet. ISO 15926 provides the means to do that in the form of XML documents that are based on the data model and the reference data library. These XML documents can be transformed to the commonly known formats, like data sheets, line lists, instrument index, cable schedule, etc.
A computer system is like an ice berg: the user only sees a small portion of it.
In order to arrive at an easy-to-use data handling environment a number of things have to be done first:
The data model is transformed to an XML Schema;
From that we build so-called 'templates' with a number of rules (e.g. for referential integrity), that can be re-used thousands of times, and that are data-driven by making reference to individuals and classes;
With these templates we define, for the various types of equipment, so-called Object Information Models ('OIM'). These are describing what kind of information is normally recorded for that type of equipment during its entire life time.
Until this point this information is part of the standard, be it that the OIMs will evolve due to the input from domain experts all over the world.
Any user organization then makes the following preparations:
They map ('translate') the data elements in their computer systems to templates;
They define so-called Document Templates. These define 'documents', that can be ordinary documents, like data sheets, or files (such as the input file of an engineering program). These documents use a view on the applicable OIMs to precisely define the information content of their documents types. This means, for example, that different data sheets for the same equipment type use different views of the same OIM.
Once these preparations have been completed the user organization can start producing XML files for information exchange, integration, and/or hand-over.
ISO 15926 defines the so-called 'Façade'. This is a web server with a relational data base that can store all exchanged XML files in a manner that results in a full 4D integration of the information. This '4D' means that the information is integrated in space and time.
If all information about a plant is brought together in such a Façade one can reproduce the information that represents the 'State of the Plant' at any time in the past, the present, and the future (e.g. construction plans).
In principle a Façade only stores the information produced by the owner of that Façade. Since information is never 'stand-alone' this means that any related information, owned by others, must be automatically fetched from one or more other Façades, via the Internet. This means: no duplication of information, so less chance of data corruption.
Façades operate on a peer-to-peer basis.
With a Façade Browser one can read the information of a set of Façades as if it were stored on one's own Façade.
The chain of Façades starts at a small System Façade for each application program. The data created with that program are mapped and stored in that System Façade. From there onwards the data exchange between Façades follows a standard pattern.
The Façade Browser is based on standard web browsers (like Internet Explorer or Mozilla). It can produce screen layouts that are based on the Document Templates of the user organization or of others (e.g. standard ISA specifications).
This is done by a transformation from the XML document to a presentable format.
The Façade Browser software also has the possibilities of a 'normal' browser. This means that it can present a mix of both the textual HTML-based information as well as data from the Façade(s).
Information from systems look compliant from the Internet
Publishing, Exchange, and Handover
Three modes of interaction between Façades are supported:
Publishing - the owner of the information puts it on his/her Façade and it can be accessed by others;
This is like publishing it on an Extranet.
Exchange - the owner of the information sends a 'message' with one or more XML 'documents' to another Façade;
This is like sending (a copy of) a document (e.g. a Purchase Order), for legal and business reasons.
Hand-over - the owner of the information transfers his/her ownership to another Façade, thereby also phyiscally transferring the related records.
This Custody Transfer goes, for example, in parallel with the Custody Transfer of a plant unit from an
EPC contractor to a plant owner/operator.
The access to the Reference Data Library, as well as the software for the Document Template Builder, the Mapper, the Façade, and the Façade Browser will be, once produced, free of charge.
The software industry is invited to come with enhanced systems with more sophisticated functionality.
Part 2 of ISO 15926, defining the data model, has been issued as an International Standard.
Part 4 of ISO 15926, defining the Reference Data Library, is in the process of being issued for ballot as a DIS (Draft International Standard).
Part 7 of ISO 15926, defining the implementation methods, mainly in XML Schema and XML, is due for ballot as a Technical Specification.
The next step to be taken is to execute a project in which all Part 7 software is programmed and tested on pilot projects.
For futher information visit www.infowebml.org or contact [suppressed]