Estado de trance

Developing the identified gaps in the current knowledge, this research proposes the development of a mechanism for enabling and assessing system interoperability through time. The MI domain was chosen as a suitable domain to develop the solution, which also required work to define the domain to the required level of rigor.

Figure 4-3 describes how this approach meets the requirements detailed in the previous section by continuing the geometrical analogy: A MI domain Foundational Ontology or Core Concept Ontology (see section 2.6.6.8) is built upon a clear scope definition and used to define individual the systems, which in this case are represented by geometrical shapes.

The foundational ontology, which may be supported by more specialised domain ontologies, in this example would be geometrical form descriptors. This ontology can be used to

describe the individual systems and over all form as they change over time because they still conform to the foundational geometrical descriptors The individual systems can be designed to ‘fit’ together to form the overall system consistently due to this common foundation, and while the individual systems and processes may change over time, represented in this case

by the different scale of shape of the geometries, the functionality is retained and further developed.

Figure 4-3 - Ontology based solution

The solution concept is able to identify where system interoperability is occurring or required and ensures interoperability by answering the competency questions defined in section 4.3.1. and constraining the system definition in line with explicit logic that defines the requirements for interoperability. The proposed solution answers these questions through a combination of core logic as new systems are declared to it, and user interaction or queries.

As new systems are declared to the solution, it develops and expands both through explicit declarations from the user and inferred knowledge using the embedded system rules.

The proposed solution uses a common MI foundation ontology (which is a Core Concept Ontology) which is specialized to form various domain ontologys for the different areas across which the MI information flows for the purpose of specifying or describing the relevant systems and processes. These domain ontologies will be consistent because they use the same foundation, however, they will require the rigour and machine interpretability of a heavyweight ontology.

The proposition is: because the foundation ontology embodies the core foundational requirements of MI, even emerging MI concepts and relationships can be defined from this foundation in a manner consistent with the existing ontologies.

Figure 4-4 shows the capability of the proposed solution and how it extends the current state of the art.

Figure 4-4 - The solution proposal capability

Figure 4-5 shows the proposed multi level ontology approach as proposed for MI. The foundation ontology is applicable on a much wider scope than Manufacturing intelligence systems due to its level of abstraction, This foundation ontology’s scope can be described as

‘Systems’. The more specialised core concept ontology developed from the foundation ontology narrows in scope, to focus on Manufacturing Systems. It is at the domain ontology level that the scope is specialised to Manufacturing Intelligence systems, with the final level of specialisation being the specific instances that populate the knowledge base. It is

important to note that the instances may not conventionally be considered part of the

ontology, but the proposed solution will rely on the populated instances to function therefore in this case they are an integral part of the ontology solution.

Figure 4-5 - The specialised ontology levels scope

Figure 4-6 - The specialisation of ontologies from Foundation to Domain instances

Figure 4-6 shows the foundation ontology being used to defined two core concept ontologies, which are then used to define a number of domain ontologies. A potential example would be a Manufacturing System and Communication System core concept

ontology, which could both be defined from the same Systems foundation ontology. These two ontologies would be consistent due to the use of a common foundation.

This approach builds on research in the field of ontology based interoperation (see

Chapter 2). The further development that will be required to meet the requirements of MI, will be the development of this method to address change over time i.e. applying an additional time axis to Figure 4-6.

Figure 4-7 shows the Foundation ontology being specialized, but also shows that the foundation ontology provides consistency and enables interoperation within a single time snapshot, and also that the persistence of this foundation ontology will provide this capability through time. The rate of change within the individual domains i.e. the rate of progress through versions does not need to be uniform or constant across the various domains.

Figure 4-7 - The heavyweight Foundation ontology providing a consistent basis through time

Figure 4-7 shows the domain consistency being maintained through time. Figure 4-8 shows that either new systems can be added to the domain or new versions of any system can be added, with the heavyweight ontological rigor ensuring that the interactions with existing systems are understood and that system or version has been designed in line with the logical constraints for interoperability. If it is not, the solution will prompt the user for more information or flag the error.

Figure 4-8 - The solution enables the addition of new systems or versions ontology or knowledge base.