Semantic Modelling and Semantic Interoperability - FAMOUS-2

 
Developing and operating Space Systems implies complex activities involving many parties, distributed in location and time. This development requires efficient and effective interoperability during the overall space system development and operations lifecycle.

Interoperability is often described from a syntactic viewpoint, focusing on data exchange formats. While syntactic interoperability is required, the pre-requisite for any successful information exchange is to ensure that all actors involved share a common understanding of the information that will be exchanged. This aspect of interoperability is known as semantic interoperability. Semantic interoperability focuses on “what” is being exchanged, while syntactic interoperability focuses on “how” it is being exchanged. 

The need for semantic interoperability is described in the ECSS-E-TM-10-23A (a technical memorandum of the European Cooperation for Space Standardization, www.ecss.nl). Addressing the task of "working together", this technical memorandum aims to define a mechanism whereby data can be reliably and effectively exchanged between all suppliers and customers involved, between all engineering/quality/management disciplines involved, at all levels of the space system decomposition, within and across all space system life cycle phases. 

FAMOUS, the fact based modelling unifying system R&D, looks at offering a solution to semantic modelling and semantic interoperability.
FAMOUS includes a generic language to formally express the semantics and related methodology for capturing that semantics. That language is based on first order logic and associated with a controlled natural language to ensure successful communication with all stakeholders.

Looking for "semantic modelling", within the FAMOUS-2 TRP activity:

• the specification of the FAMOUS language has been formally expressed extending the FBM language developed by the FBM community. The FAMOUS language is formally specified using ORM, the object role modelling language (refer to www.orm.net, ORM is one of the several existing fact based modelling languages). The corresponding ORM model has been captured in NORMA (refer to www.ormsolutions.com  for the freeware version of NORMA).
• the FAMOUS methodology has been drafted. The methodology specifies means to properly develop conceptual data models, integrating the needs of each stakeholder in a global conceptual model in consistency with the required information life cycle.

Models developed using FAMOUS can be visualized graphically (using the ORM2 formal graphical language) but also verbalized using a controlled natural language that enables each stakeholder to fully validate the semantics contained within the models.
Semantic modelling using FAMOUS allows capturing the WHAT. Applying FAMOUS to the development of Space Products, modelling the semantics is of the responsibility of each customer to ensure that their product specification is fully and clearly defined before initiating the development of the product by the supplier(s).
In support to the development of information systems, within the FAMOUS-2 TRP activity, the algorithms required to automatically transform conceptual models in logical and physical models (relational, hierarchical, object oriented) ready for deployment in software solutions have been specified. Such automatism ensures the quality of the generated logical models (e.g. fulfilling the standardized normal form rules of relational modelling).

Objectives
The objectives of FAMOUS-2 TRP activity were:

• to formally specify the FAMOUS language to allow modelling 100% of the WHAT, in line with the ISO TC97/SC5/WG3 TR9007:

- Helsinki principle:
"Any meaningful exchange of utterances depends upon the prior existence of an agreed set of semantic and syntactic rules. The recipients of the utterances must use only these rules to interpret the received utterances, if it is to mean the same as that which was meant by the utterer."

                > FAMOUS enables semantic modeler to comply with the Helsinki principle.

- 100 % principle:
"All relevant general static and dynamic aspects, i.e. all rules, laws, etc., of the universe of discourse should be described in the conceptual schema. The information system cannot be held responsible for not meeting those described elsewhere, including in particular those in application programs."

                 > FAMOUS offers means to model the semantics in a way that is far better than what one can do with the "modelling at logical level" technology currently used by most modelers.

- Conceptualization principle:
"A conceptual schema should only include conceptually relevant aspects, both static and dynamic, of the universe of discourse, thus excluding all aspects of (external or internal) data representation, physical data organization and access as well as all aspects of particular external user representation such as message formats, data structures, etc."

                  > FAMOUS complies with that principle.

• to formally specify means to exchange conceptual models with other fact based modelling languages, e.g. ORM, CogNIAM, DOGMA, FCO-IM, OWL

                  > FAMOUS-2 has partially covered these translations, except for ORM that is fully covered since FAMOUS reuses and adds to the ORM formalism.

• to formally specify the algorithms required for automatic generation of logical models such as:
  • the relational logical models used e.g. by for the development of SRDBs (Satellite Reference Databases)
  • the object oriented (UML, ECORE) logical models used e.g. by real-time software
  • the hierarchical (e.g. XSD) logical models used to exchange data between different information systems

                 > FAMOUS-2 has partially covered these formal transformation specifications.

• to verify and validate the FAMOUS language, methodology and transformation prior to initiate the development of the FAMOUS tool

                 > Prototypes using and updating the NORMA tool have been developed to demonstrate the adequacy of many FAMOUS specifications. Additional prototypes are required to fully verify and validate the FAMOUS specification.

Achievements and status
FAMOUS is built using decades of academic research related to fact based modelling, more globally known as semantic modelling or ontology modelling. Despite this so long history in University, worldwide, very little knows about FBM and billions of Euros are spent by Industry developing software and information systems that do not or poorly comply with their stakeholder needs. This is also true in the Space Business. In 2009, the Agency has organized a standardization working group made of worldwide academic experts in Fact Based Modelling to transfer their knowledge to Industry (refer to www.factbasedmodeling.org). FAMOUS plays a key role in this transfer of academic knowledge to Industry. FAMOUS addresses the need of the Space Industry focusing on the known problematic of large system developments: “how to work together, reducing risks and costs, being successful”.

Benefits
FAMOUS is still a specification but tools such as NORMA or CogNIAM Studio can already help in successfully developing information systems. FBM modelling using FBM tools will create the pavement for solving the semantic interoperability issue.

Next steps
The next step for FAMOUS should include:

• additional research for enhancing FAMOUS e.g. with reasoners, fully formalizing all transformation to logical models
• full system and software specification of the FAMOUS tool
• development of the FAMOUS tool

For additional information related to FAMOUS 2, refer to www.famous2.eu