# Smart Factory Web--A Blueprint Architecture for Open Marketplaces for Industrial Production
## 5 Smart Factory Web Approach
### Factory Registration and Interoperability  
One of the main tasks of a marketplace is to provide registration and search services. However, usually, the barriers to information acquisition are high, mainly due to syntactical and semantic interoperability problems in both the provision of information and the use of the information provided. Regarding registration, providers typically have their own model of services and products, which usually does not match the internal model of the marketplace. As manual registration is a time-consuming and error-prone activity, there is a need for methods and tools to facilitate automated registration. SFW solves syntactic interoperability by using standard communication protocols (e.g., [[https://datatracker.ietf.org/doc/html/rfc2818](https://datatracker.ietf.org/doc/html/rfc2818)]([https://datatracker.ietf.org/doc/html/rfc2818](https://datatracker.ietf.org/doc/html/rfc2818)), accessed on 15 July 2021), common data formats (e.g., IEC 62471 AutomationML ([[https://www.automationml.org/o.red.c/publications.html](https://www.automationml.org/o.red.c/publications.html)]([https://www.automationml.org/o.red.c/publications.html](https://www.automationml.org/o.red.c/publications.html)), accessed on 15 July 2021) and IETF JavaScript Object Notation (JSON ([[https://datatracker.ietf.org/doc/html/rfc7159](https://datatracker.ietf.org/doc/html/rfc7159)]([https://datatracker.ietf.org/doc/html/rfc7159](https://datatracker.ietf.org/doc/html/rfc7159)), accessed on 15 July 2021))), com  
Figure 4: Smart Factory Web architectural details. mon architectural styles (e.g., REpresentational State Transfer (REST) ([[https://tools.ietf.org/id/draft-keranen-t2](https://tools.ietf.org/id/draft-keranen-t2) trg-rest-iot-05.html]([https://tools.ietf.org/id/draft-keranen-t2](https://tools.ietf.org/id/draft-keranen-t2) trg-rest-iot-05.html), accessed on 15 July 2021)) and standard communication frameworks (e.g., IEC 62541 OPC UA ([[https://opcfoundation.org/developer-tools/specifications-unified-architecture](https://opcfoundation.org/developer-tools/specifications-unified-architecture)]([https://opcfoundation.org/developer-tools/specifications-unified-architecture](https://opcfoundation.org/developer-tools/specifications-unified-architecture)), accessed on 15 July 2021)). On the other hand, semantic interoperability requires a precise interpretation of the information provided by the marketplace players in order to understand it. Smart Factory Web describes factories as a hierarchy of assets, including their capabilities and properties. This data model is represented in the SFW ontology in Figure 5.  
The individual ontology concepts are defined in more detail in Table 5. Table 5 describes the required ontology concepts for modeling production, process steps and supply chains. The relations between the concepts are defined in Table 6. The respective inverse relation is shown in italics. The SFW capability ontology is the right way to achieve semantic interoperability. However, it is expected that either:  
* Providers are aware of the SFW capability ontology and have prepared their registration information as instances of this ontology, or;
* Developers should be involved to ensure that provider information is accurately mapped to the SFW capability ontology. This requires negotiation with each provider individually to agree the mappings. Figure 5: Smart Factory Web ontology.