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  • A Survey of Industry Data Models and Reference Data Libraries


    9 General purpose product dictionaries and classification schemes 

  • 9.1 Introduction 

    Clause 9 covers general purpose product dictionaries and classification schemes.  The building classification scheme uniclass-2015 is discussed in clause 3.2, and the ISO 15926 reference data library for process plants is discussed in clause 8.5. 

    9.2 eCl@ss 


    9.2.1 Defining organization 

    The eCl@ss dictionary is maintained  by the eCl@ss Association.  This was founded in 2000 by 12 large German companies.  The eCl@ss association now has more than 150 members, which include businesses, associations and public institutions. 

    9.2.2 Objectives and scope 

    The introduction to eCl@ss says that it: 

    [ … ] standardizes procurement, storage, production, and distribution activities in and between companies - across sectors, countries and languages. 

    9.2.3 Structure of the model 

    eCl@ss has 45,000 product classes and 19,000 properties.  These are divided into subject areas as follows: 

    • Development (Service) 
    • Logistics (Service) 
    • Maintenance (Service) 
    • Food, beverage, tobacco 
    • Machine, device (for special applications) 
    • Equipment for mining, metallurgical plant, rolling mill and foundry 
    • Information, communication and media technology 
    • Packing material 
    • Plant equipment, tool 
    • Construction technology 
    • Machine element, fixing, mounting 
    • Office product, facility and technology, paper 
    • General service 
    • Energy, extraction product, secondary raw material and residue 
    • Electric engineering, automation, process control engineering 
    • Vehicle (complete vehicle) 
    • Home economics, Home technology 
    • Auxiliary supply, additive, cleaning agent 
    • Polymer 
    • Laboratory material, Laboratory technology 
    • Installation (complete) 
    • Medical Device 
    • Semi-finished product 
    • Machine, apparatus 
    • Industrial piping 
    • Inorganic Chemical 
    • Organic Chemical 
    • Occupational safety, accident prevention 
    • Marketing 
    • In-vitro diagnostic 
    • Optics 
    • Automotive engineering, vehicle component 
    • Human and veterinary drug, pesticide as well as active ingredient 
    • Clothing and textile 
    • Body care, personal hygiene 
    • Sport, playing, leisure 
    • Public safety and military technology 
    • Interior furnishing 
    • Fluid power 
    • Interim class (unspecified) 

    The representation of the classes and properties is according to IEC 61360-1 “Standard data element types with associated classification scheme - Part 1: Definitions - Principles and methods” (https://webstore.iec.ch/publication/28560). 

    A key strength of the eCl@ass dictionary is that it specifies properties for classes. 

  • 9.2.4 Documentation 

    eCl@ss provides good browsing and querying software for the classes and properties. 

    9.2.5 Maintenance and usage 

    The eCl@ss dictionary is actively maintained, and a new release is published every year. 

    The eCl@ss dictionary is widely used in industry. 

    9.3 ISO/IEC Common Data Dictionary (CDD) 


    9.3.1 Defining organization 

    The ISO/IEC Common Data Dictionry (CDD) is defined by a maintenance agency operated jointly by ISO and IEC. 

    Formerly the CDD was the IEC standard IEC 61360-4, which has been withdrawn. 

    9.3.2 Objectives and scope 

    The introduction to the CDD says: 

    The IEC Common Data Dictionary (IEC CDD) is an International Standard (IEC 61360-4 DB) and serves as a common repository of concepts for all industrial/technical domains (electrotechnical and non-electrotechnical; e.g. industry, building, energy, healthcare, …) based on the methodology and the information model of IEC 61360 series, and provides 

    • unambiguous identification of classes and properties, and their relations; 
    • commonly accepted terminology and definitions based on accepted sources such as IEC International Standards, other International Standards, industry standards, or public authorities; 
    • hierarchies of concepts enabling users to appropriately characterize their products and services; 
    • relevant conditions and constraints if necessary on possible values of characteristics; 
    • technical representation of concepts including units and data types and their identification. 

    [The introduction is no longer quite correct.  The IEC CDD is not IEC 61360-4, which has been withdrawn, but defined by a maintenance agency operated jointly by ISO and IEC.] 

    9.3.3 Structure of the model 

    The IEC CDD hosts different product classifications (based on international standards) for 

    • process automation equipment (based on IEC 61987); 
    • low voltage switchgear and control gear (based on IEC 62683); 
    • electro-electronic components (provided by IEC TC47); 
    • optics (based on ISO 23584); 
    • measuring instruments (based on IEC ISO 13584-501); 
    • environmental declaration (based on IEC 60721). 

    The content of the CDD is therefore similar to that of eCl@ss, but with items having a status assigned by the ISO/IEC maintenance agency. 

    9.3.4 Documentation 

    The CDD has browsing and querying software for the classes and properties maintained by IEC. 

    The transfer of hosting of the CDD to eCl@ss is being considered. 

    9.3.5 Maintenance and usage 

    The level of maintenance of the CDD is difficult to determine because revision information is published item by item.  However the top class component has been revised more or less annually with the latest [in August 2020] revision in January 2020. 

    [It is unclear what “revision” means here.  Most likely it is any change to its subclasses. DL] 

    The CDD dictionary is widely used in industry. 

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