Initial Situation
Every system is engineered to operate in some distinct context. As the context influences the system it is important to properly document the context and the relations to the system under development. For cyber-physical systems (CPS) the context is not only source of requirements shaping the system but, furthermore, CPS heavily rely on perceiving their current context by sensors and changing their context by adaptors. To cope with these complex interactions, modeling the context and relating the context model to the system model has proven itself useful.
Modern CPS operate in open and dynamic contexts posing new challenges to the modeling of the CPS’ context. In addition, CPS collaborate to build system-of-systems at runtime. Thus, the single CPS becomes part of a larger CPS. In doing so, system and context boundaries change, parts of the context become part of the system and vice versa when CPS part. As CPS operate in open and dynamic contexts the concrete composition of the system-of-systems is hard to foresee as depending on the concrete situation different CPS will join together to build a system-of-systems.
Solution Approach
In the ContextCPS project we investigate the formation of systems-of-systems in dynamic and open contexts and develop a modeling solution for the correct specification of CPS.
Goals
Ontological basis
To properly document the context of CPS a context ontology is needed describing the characteristics of open and dynamic context. An ontological basis is first desired to ensure proper engineering of CPS that operate in open and dynamic context, i.e. it allows taking the specific characteristics into account when specifying the system under development. Furthermore, context ontologies are used at runtime to ensure interoperability between different systems. In this case systems exchange and relate their ontologies to one another which ensures proper communication and exchange of messages and command signals. In this project, we aim at defining such an ontological basis for CPS operating in open and dynamic context. Based on existing works on context definition and modeling we will develop a context ontology for CPS that takes the open and dynamic nature of the context into account.
Dynamic system boundary
To engineer a CPS to be able to partake in different system-of-systems means that we need to adapt our engineering methods to allow for changing system and context boundaries. Therefore, the second goal of the ContextCPS project is to develop a modeling method that allows considering two different types of systems and their boundaries: the CPS and the system-of-systems. The modeling method shall allow defining two context types for these respective systems. To account for dynamicity, they closely depend on each other but are able to contribute to different shapes a system-of-systems can take. Thus, based on one model multiple situations shall be described and analyzed.
Modeling language
Finally, for the third goal of ContextCPS the findings from the context ontology and the method to define dynamic system and context boundaries between CPS and system-of-systems results shall be incorporated to define a context modeling language that accounts for the peculiarities of CPS operating in open and dynamic contexts.
Contact Person
Funding
SSE funded