# Semantic Web and Knowledge Graphs for Industry 4.0
## 5 Semantic Web and Ontologies for Industry 4.0
### Ontologies for Industry 4.0 Manufacturing
The ontology development process followed the five stages of ontology engineering methodology that are feasibility study, kick-off, refinement, evaluation, and usage and evolution. According to [PERSON] et al. Manufacturing resource capability ontology (MaRCO) is used by resource vendors to represent the capabilities of resources they are offering and publish it in the digital marketplaces or global resources list and is browsed by production companies or systemsintegrators when reconfiguring existing or designing new manufacturing system. MaRCO aims to provide the matchmaking between the required capabilities of a resource and the production requirements of a product. [PERSON] et al. investigated and extracted the context and information from Reference Architectural Model Industrie (RAMI 4.0) [64], to integrate the industry 4.0 process by suggesting an ontology approach. This information was extracted from different sources, standards, architectures, and model relevant to I4.0. The ontology objective is to give an overview of the RAMI4.0 key concepts and its relationships to enable the identification of inconsistencies, gaps, and redundancies in its layers descriptions and definitions for I4.0 process development. They carried out a middle-out approach to analyze the layers of RAMI4.0 and broke down the sentences referring to the information layer and shift it into a concept map. Semantic Manufacturing Ontology highlights the sequence of processes and machines required for an ordered workpiece (product) [65], turtle file is available online ([[http://i40.semantic-interoperability.org/smo/smo.ttl](http://i40.semantic-interoperability.org/smo/smo.ttl)]([http://i40.semantic-interoperability.org/smo/smo.ttl](http://i40.semantic-interoperability.org/smo/smo.ttl)), accessed on 1 May 2021). [PERSON] et al., proposed CDM-Core ([[http://sourceforge.net/projects/cdm-core/](http://sourceforge.net/projects/cdm-core/)]([http://sourceforge.net/projects/cdm-core/](http://sourceforge.net/projects/cdm-core/)), accessed on 1 May 2021) ontology by re-using the existing domain and core ontologies [66]. The authors claimed it to be the largest publicly available global ontology. However, they have more focused on the service-oriented architecture and monitoring of the manufacturing services. There is no explicit information regarding the modelling of manufacturing factory and the main concept such as type of processing, type of machine, etc., are missing. Manufacturing system should be able to incorporate and assist human (Operators, Technicians). Human are participating in the environment of automated systems and need to consider the role of the operator in such an environment. [PERSON] et al. proposed the addition of the skills and tasks performed by humans in manufacturing ontology that is using the CPS knowledge repositories [67]. Their work presented a semantic model that allows the operations modelling achieved by human operators. However, they focused more on the service of orchestration during the production plans. [PERSON], [PERSON] et.al proposed the integration of manufacturing domain data such as Product, Process, and Resource (PPR) using the ontology approach for matching the product requirements in assembly automation [68]. The mapping information of PPR helps in deriving the processes and resources required to manufacture the designed product. Considering the modular ontologies design, Protege ([[http://protege.stanford.edu/](http://protege.stanford.edu/)]([http://protege.stanford.edu/](http://protege.stanford.edu/)), accessed on 1 May 2021) (ontology editor tool) can be used to form a graph dataset including all imported ontologies. [PERSON] et al. proposed an ontology-based approach to describe the industrial components merged from four different scenarios in order to form upper-level ontology [69]. Such a union will enable to change the created business process to boost the product customization for the customer and reduce the cost for its producers.