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A Survey of Industry Data Models and Reference Data Libraries
6 Industrial data
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6.1 Introduction
https://committee.iso.org/home/tc184sc4
ISO TC 184/SC 4 develops standards for “industrial data”. Two major families of standards have been developed as follows:
- ISO 10303 “Product data representation and exchange” which covers the design and manufacturing of mechanical parts and circuit boards, and the maintenance of equipment through its life;
- ISO 15926 “Integration of life-cycle data for process plants including oil and gas production facilities” which covers the design, construction, operation and maintenance of process plant.
The scope of the standards is illustrated by Figure 18 reproduced from the website.
Figure 18 - Scope of ISO TC 184/SC 4 standards
The scope is large and there is a correspondingly complicated architecture to support it. This architecture is not well documented as the OGC architecture or its implementation with INSPIRE.
ISO TC 184/SC 4 currently has 770 published standards (mostly within the ISO 10303 series) and 31 under development. This complexity is unsupportable, and work is going on at present to rationalise the architecture.
Th ISO 15926 series of standards is discussed along with other process industry standards in clause 8 of this document
6.2 ISO 10303 (STEP) Application Protocols
6.2.1 Defining organization
ISO TC 184/SC 4 “Industrial data” with support from industry organizations such as the Prostep ivip Association and PDES Inc..
6.2.2 Objectives and scope
A STEP Application Protocol (AP) is equivalent to an “application schema” within the OGC environment. There are two STEP APs (or families of APs) with wide industrial use:
ISO 10303-242 “Managed model-based 3D engineering”
This is widely used within the automotive and aerospace industries for storing and exchanging engineering design information.
The companion AP 209 “Multi-disciplinary analysis and design” (http://www.ap209.org/) supports the FEA and CFD analyses carried out during the design process.
These APs are used within the aerospace “Long Term Archiving and Retrieval” (LOTAR) consortium (http://lotar.prostep-ivip.org/).
ISO 10303-239 “Product Life Cycle Support” (PLCS)
This is widely used within the aerospace and defence communities for maintaining equipment and systems through their life.
6.2.3 Structure of the model
At the top of ISO 10303 is a very sparse structure devoted principally to version control shown in Figure 19.
Figure 19 - STEP product structure backbone
The STEP backbone has been extended in the different APs to support the complexity of mechanical assemblies and systems. The class product is also at the top of the IFC data model, which was initially developed within ISO TC 184/SC 4. However the “bells and whistles” for version control and assembly structures were not seen to be relevant to buildings.
6.2.4 Documentation
STEP APs are documented via the STEP Module and Resource Library (SMRL). This is a publishing environment, where the source is XML and HTML views are generated automatically.
STEP is complicated, and therefore is difficult for a domain expert to understand, in spite of the sophistication of the publishing environment.
6.2.5 Maintenance and usage
The STEP APs are actively maintained. The latest [in August 2020] revision of AP 242 was published in April 2020.
The STEP APs are widely used in the automotive and aerospace industries, and in military lifecycle support.
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6.3 Ontology for geometry and topology
6.3.1 Defining organization
ISO TC 184/SC 4/WG 12/T 1 “Industrial data - data modelling - geometry and topology”
6.3.2 Objectives and scope
At the heart of STEP is the model for geometry and topology - ISO 10303-42. STEP and the OGC standards are similar in this respect. Within OGC, a feature is linked to points, curves and surfaces on the surface of the Earth. In STEP, a product is linked to points, curves, surfaces and solids within a 3D CAD space.
The STEP geometry and topology model precedes those of the building IFCs and OGC, and both appear to have been based upon it initially. However, the models have diverged to support different requirements.
ISO TC 184/SC 4/WG 12/T 1, which is responsible for STEP geometry and topology, is carrying out a feasibility study on an ontology for geometry and topology which can bring the different geometry and topology models back together. The team also includes experts on the more modern geometry standards which have been developed to support visualisation, such as Siemens JT (https://www.plm.automation.siemens.com/global/en/products/plm-components/jt.html).
6.3.3 Structure of the model
The team will deliver its report to the November 2020 meeting of ISO TC 184/SC 4. No outline model has yet been published, but the work is included here because of its long-term importance for the National Digital Twin.
6.3.4 Documentation
Initial work has been documented in UML and OWL.
6.3.5 Maintenance and usage
It is intended that the ontology will be maintained alongside ISO 10303-42.
6.4 Core Industrial data set of terms
6.4.1 Defining organization
ISO TC 184/SC 4/AHG 1 “Industrial data - vocabulary”
6.4.2 Objectives and scope
Different teams with ISO TC 184/SC 4 extend their top-level ontologies or data models with domain-specific reference data. A good example of this is the classes and properties defined within ISO/TS 15926-4 (see clause 8.5). It is recognised that domain specific reference data libraries can be relevant to more than one top level ontology or data model. For example, aeroplanes, ships motor cars and process plants all contain pipes, pumps and valves in mechanical systems, and motors and switches in electrical systems.
A difficulty is that the developers of a reference data library often place the classes and properties that they define with respect to a particular top ontology or data model, and thereby limit the use of the reference data library. A solution to this is the creation of an intermediate level - a core vocabulary which consists of precise and understandable industrial data terms which can:
be specialised for different domains by teams of domain experts, who do not need to be concerned with the top ontologies or data models;
be mapped to different top ontologies or data models.
This enables the reference data can be used with different top ontologies or data models in different applications. The approach is illustrated in Figure 20.
Figure 20 - Role of the Core Industrial data set of terms
The core vocabulary group within ISO TC 184/SC 4 contains representatives from the teams developing the different standards within SC 4, and also from the ISO/IEC Common Data Dictionary (CDD - https://cdd.iec.ch/). The core vocabulary is seen as analogous to the Dublin Core for document metadata, and consists of about 80 terms.
6.4.3 Structure of the model
The team will deliver its report to the November 2020 meeting of ISO TC 184/SC 4. No outline model has yet been published, but the work is included here because of its long-term importance for the National Digital Twin.
6.4.4 Documentation
Initial work has been documented as a “paper” document. Representations in EXCEL and SKOS are planned.
6.4.5 Maintenance and usage
It is intended that the vocabulary will be maintained as an ISO standard.
6.5 Modeling and Simulation information in a collaborative Systems Engineering Context (MoSSEC)
6.5.1 Defining organization
ISO TC 184/SC 4 “Industrial data” with support from the industry MoSSEC consortium, which includes the manufacturers Airbus, Collins Aerospace, Boeing, and BAE Systems, and the software suppliers Eurostep, Dassault Systèmes, MSC Software, and Siemens.
The Modeling and Simulation information in a collaborative Systems Engineering Context (MoSSEC) project began outside ISO, but its deliverable is now a STEP AP (ISO 10303-243).
6.5.2 Objectives and scope
The overview of the MoSSEC project says:
The MoSSEC standard enables a proper exchange and sharing of modelling and simulation data with traceability to its systems engineering & PDM context.
This collaborative context data can be summarised as “who”, “what”, “where”, “when”, “how”, “why”.
6.5.3 Structure of the model
MoSSEC adds the object study to the STEP framework. This is an activity which investigates a “concept” and produces study reports, which are documents.
6.5.4 Documentation
The MoSSEC AP will be documented within the SMRL environment.
6.5.5 Maintenance and usage
ISO 10303-243 was approved as a Committee Draft in June 2018, and is intended [in August 2020] to be published in 2020.
