Preamble

The aim of this document is to define the structure of the Administration Shell to enable the meaningful exchange of information about assets and I4.0 components between partners in a value creation network.

This part of the document focuses on how such information needs to be processed and structured. In order to define these specifications, the document formally stipulates some structural principles of the Administration Shell. This part does not describe technical interfaces of the Administration Shell or other systems to exchange information, protocols, or interaction patterns.

This document focuses on:

This document presumes some familiarity with the concept of the Asset Administration Shell. Some of the concepts are described in Annex A for convenience’s sake. The concepts are being standardized as IEC standard IEC 63278 series [44]. The main stakeholders addressed in this document are architects and software developers aiming to implement a digital twin using the Asset Administration Shell in an interoperable way. Additionally, the content can also be used as input for discussions with international standardization organizations and further initiatives. Please consult the continuously updated reading guide [38] for an overview of documents on the Asset Administration Shell. The reading guide gives advice on which documents should be read depending on the role of the reader.

All clauses that are normative have "(normative)" as a suffix in the heading of the clause.

Clause Terms, Definitions and Abbreviations provides terms and definitions as well as abbreviations, both for abbreviations used in the document and for abbreviations that may be used for elements of the metamodel defined in this document.

Clause Introduction gives a short introduction into the content of this document.

Clause General summarizes relevant, existing content from the standardization of Industry 4.0; i.e. it provides an overview and explains the motives, but is not absolutely necessary for an understanding of the subsequent definitions.

Clause Semantic Identifiers for Metamodel and Data Specifications defines how to create semantic identifiers for the elements of the metamodel itself.

Clause Specification (normative) is the main normative part of the document. It stipulates structural principles of the Administration Shell in a formal manner to ensure an exchange of information using Asset Administration Shells. A UML diagram has been defined for this purpose.

Clause Data Specification Templates (normative) explains how to define predefined data specifications, including those for defining concept descriptions. A discussion on the difference of data specification templates, inheritance, qualifiers and categories can be found in the Legend for UML Modelling#templates-inheritance-qualifiers-and-categories[Annex].

Clause Mappings (normative) provides information on the exchange of information compliant to this specification in existing data formats like XML, JSON, or RDF. For this purpose additional formats are defined as well as needed text serializations of complex types.

Clause Summary and Outlook summarizes the content and gives an outlook on future work.

Annex Concepts of the Administration Shell contains additional background information on Asset Administration Shell, while a mapping to the requirements can be found in Annex B.

Annex Requirements collects the requirements from various documents that have impact on the specific structure of the Administration Shell and explains how the requirements is solved in the specification.

Annex ValueOnly-Serialization Example and example of a Value-Only serialization as explained in Clause Mappings is given.

Annex Backus-Naur-Form defines the grammar language used in the specification. Annex Legend for UML Modelling contains information about UML, while Annex xef:annex/uml-templates.adoc[] provides the tables used to specify UML classes etc. as used in this specification. Handling of Constraints explains the numbering of constraints used in the specification.

Annex How to Use the Metamodel provides some hints for modelers. Annex Metamodel UML with Inherited Attributes shows selected metamodel diagrams including all inherited attributes for developers.

The Metamodel Changes describes metamodel changes compared to previous versions.

Finally, a Bibliography is given.

The work is based on the following principle: keep it simple but do not simplify if it affects interoperability.

To create a detailed specification of the Administration Shell according to the scope of Part 1 result papers published by Plattform Industrie 4.0, the trilateral cooperation between France, Italy, and Germany, as well as international standardization results were analyzed and taken as source of requirements for the specification process. As many ideas as possible from the discussion papers were considered. See Annex Concepts of the Administration Shell for more information.

The partners represented in the Plattform Industrie 4.0 and the Industrial Digital Twin Association (IDTA) and associations such as ZVEI, VDMA, VDI/ VDE and Bitkom, ensure that there is broad sectoral coverage of process, hybrid, and factory automation and in terms of integrating information technology (IT) and operational technology (OT).

Design alternatives were intensively discussed within the working group. An extensive feedback process of this document series is additionally performed within the working groups of Plattform Industrie 4.0 and IDTA.

Guiding principle for the specification was to provide detailed information, which can be easily implemented also by small and medium-sized enterprises.