Towards an OPC UA Compliant Programming Approach with Formal Model of Computation for Dynamic Reconfigurable Automation Systems This paper proposes Service Oriented SystemJ xe2x80x93 OPC UA (SOSJ  OPC UA), a serviceoriented programming approach which targets dynamic industrial manufacturing systems. An extension of SOSJ, SOSJ  OPC UA utilizes OPC UA standard to introduce service orientation, enable interoperability with different actors in the systems, and compliance with Reference Architecture Model for Industrie 4.0 (RAMI 4.0) which defines OPC UA as the communication standard. The paper begins by describing new concept on the synergy of SOSJ and OPC UA. Then, SOA information exchange mechanisms which utilize OPC UA are defined that enable parties to find each other. SOSJ xe2x80x93 OPC UA is then demonstrated in a simple manufacturing example to demonstrate its capability.

A formal mapping between OPC UA and the Semantic Web The communication protocol OPC UA is one of the most important IIoT enablers within the automation domain. OPC UA not only aims to provide interoperability on the transport layer, but also interoperability of the semantic layer shall be addressed based on socalled Companion Specifications. However, the lack of OPC UA formal semantics makes automatic validation of OPC UA data models impossible. Another drawback is the shortage of available tools for OPC UA, such as an implementation of the query engine for the specified OPC UA query language. In this paper we provide a formal translation of OPC UA models to the Semantic Web standard OWL, thus making OPC UA implicit semantics, that is described in the documentation, explicit, by means of OWL axioms. Moreover, we outline how this mapping can be used to offer validation and querying of OPC UA data models based on already existing Semantic Web technology.