Estudio calorimétrico de las piezas cargadas con CHX y TCS

To extract information about standards, we searched documents of standardization frameworks for I40. Figure 4.6(b)shows the utilized criteria for searching relevant documents related to standardization frameworks for I40. We started by combining terms such as “Industry 4.0”, “Reference Architectures”, “Standardization Landscape”, and “Standards”. These combinations

allowed to retrieve documents of standardization frameworks that categorize standards, e.g., the RAMI4.0 Model [20] and the IIRA architecture [7]. By following this search process a list of documents of standardization frameworks describing standards is compiled. For each framework in the list, an RDF molecule with the name and URI of the framework are created in the I40KG.

Furthermore, to retrieve organizations that publish or develop standards, we used the terms “Standardization Organizations”, “Industry 4.0”, “Standards”, and “Reference Architectures”.

4

https://www.posccaesar.org/wiki/ISO15926inOWL

4.1 I40 Knowledge Graph Creation

(a) Documents per standards

Search en- gines Keywords Period google.com, google schoolar, ask.com, bing.com “Standardization Frameworks”, “Standards”, “Relations”, “Smart Manufacturing”, “Industry 4.0”, “Industrie 4.0”, “Reference Architectures”, “Standardization Landscape”, “Internet of Things”, “Standardization Organizations” 12.2002 - 07.2017

(b) Search criteria for selecting documents

Figure 4.6: Number of consulted documents per standards and utilized search criteria. Figure

4.6(a)shows the number of consulted documents in the X-axis. The Y-axis depicts the number of standards

molecules that are created with a given number of documents, e.g., to create the molecules of AML and OPC UA, ten documents are consulted. Figure4.6(b)outlines the search engines, the keywords as well as the period in which the retrieved documents are published.

The terms are introduced on the Web engines and the first top ten documents are retrieved and analyzed. We compiled a list of 30 standardization organizations. For each organization in the list, an RDF molecule with the name of the standardization organization and its URI is introduced in the I40KG. An RDF molecule is defined as a set of triples sharing the same subject [61]. The name of the organization is searched in the Web engines. In case the organization contains an official page, its link is added to the RDF molecule. From its official page, the acronym and the formation date are retrieved. Additionally, if the links to Wikipedia and DBpedia exist, they are also added to its molecule. Listing4.1 depicts the RDF molecule of the OPC Foundation as instance of the class sto:StandardOrganization. OPC Foundation is the organization that developed the OPC UA standard.

@prefix sto:<https://w3id.org/i40/sto#>.

@prefix rdfs: <http://www.w3.org/2000/01/rdf−schema#>. sto:OPC_Foundation a sto:StandardOrganization ;

rdfs:label "OPC Foundation"@en;

rdfs:comment "Industry consortium that creates and maintains..."@en;

sto:abbreviation "OPC";

sto:formationDate "1994-01-01"^^xsd:date;

sto:hasDBpediaResource <http://dbpedia.org/page/OPC_Foundation>; sto:hasOfficialResource <https://opcfoundation.org/>;

sto:hasWikipediaArticle <https://en.wikipedia.org/wiki/OPC_Foundation>.

Listing 4.1: Description of the RDF Molecule of the OPC Foundation

Then, Algorithm1computes a list of standards which are described in the retrieved documents of the standardization frameworks. Standards are searched on the retrieved documents using the pattern “publishing organization” and “numeric value”, e.g., IEC as the organization and 62541 as the numeric value. In addition, the algorithm creates a list with the mappings among the standards and the standardization frameworks.

Chapter 4 Integrating Industry 4.0 Standards into a Knowledge Graph

Algorithm 1 Extract information of standards from documents Input: stdFrameworkDocList, stdOrganizationList

Output: StandardList, MappingsStandardFrameworkList

1: procedure ExtractStandardsInfo

2: for each doc in stdF rameworkDocList do :

3: stdF ramework = stdF rameworkDocList.getStdF ramework()

4: std = doc.searchStandardByN ame([P ublishingOrganization + numericV alue])

5: createStdList(hstd, U RIi)

6: createM appingList(hstd, stdF rameworki)

The mapping to standardization frameworks enables the link of existing standards to respect- ive frameworks. We investigated standardization frameworks comprising information about classifications of standards. Typically, this classification is performed in dimensions or layers and is made according to the function of the standard. RAMI4.0 classifies standards according to three general dimensions, i.e., IT, Life-Cycle and Value Stream, and the Hierarchy Level. For example, the IT dimension of RAMI4.0 is analyzed. The layers which belong to the IT dimension are considered, from the Asset to the Business layer (cf. Figure4.1(a)). Furthermore, standards are mapped to the specific layers of this dimension. The Administration Shell can be considered as other standardization framework that classifies standards. In this case, it delineates how standards are linked to submodels. The submodels enclose the different functions of that an asset requires, e.g., identification, communication, or engineering [6]. The Identification submodel is aligned with the ISO 29005 standard, whereas the Communication submodel with the IEC 61784 Fieldbus Profiles (cf. Figure 2.2). For instance, the engineering submodel is aligned with standards such as IEC 61360, IEC 61987, and eCl@ss.

The step of extracting information of standards from unstructured data sources allows for representing this knowledge using the STO ontology. Furthermore, the knowledge is encoded in the I40KG. Hence, the interoperability conflicts SIC1, SIC2, and SIC4 existing across the data sources describing standardization frameworks and standards, are resolved during this step.