Dr Yannis Kalfoglou: Interoperability

Time has long gone when manufacturers designed and assembled artefacts as stand-alone objects, ready to be used for whatever purpose they had been originally conceived. The necessity for more and more complex devices and the standardisation of manufacturing processes have led to the engineering of very specialised components that can be reused for a variety of component-based systems, which neither have been designed nor assembled by a sole manufacturer and for a unique purpose.

Analogously, in our information age, a similar phenomenon has occurred to the ``manufacturing'' of IT artefacts. Originally, software applications, databases, and expert systems were all designed and constructed by a dedicated group of software or knowledge engineers, which had overall control of the entire lifecycle of IT artefacts. But this time has gone too, as software engineering praxis is shifting from the implementation of custom-made, stand-alone systems to component-based software engineering (COTS, ERP, etc.); databases are gradually deployed in distributed architectures and subsequently federated; and knowledge-based systems are built by reusing more and more previously constructed knowledge bases and inference engines.

Moreover, the World Wide Web, and its ambitious extension, the Semantic Web, has brought an unprecedented global distribution of information in form of hypertext documents, online databases, open-source code, terminological repositories, web services, blogs, etc., which continually challenge the traditional role of IT in our society. As a result, the distributed nature of IT systems has experienced a dramatic explosion with the arrival and generalised use of the Internet major IT suppliers starting to provide on demand web-based services (empowered by Service Oriented Architectures) instead of all-in-one boxed products and localised solutions (fine-tuned against the legal system, currency, and accountancy policy in each country) instead of universal solutions.

But in contrast to traditional industrial manufacturing and composition of artefacts, the composition and interaction of IT components at the level of distribution on the Web is still at its infancy, and we are just grasping the scope of this endeavour: successful IT component interoperability beyond basic syntactic communication is very hard. Unlike with industrial manufacturing, our era's basic commodity around which all IT technology is evolving, namely information, is not yet well understood. While industrial and civil engineers know how to apply well-established mathematical models to derive an artefact's characteristics from the physical properties of its components, software engineers and knowledge workers lack the machinery that will enable them to do the same with information assets. The problem with understanding information, is that we need ways with which we can reveal, expose and communicate the semantic aspect (semantics) of information. But as soon as we try to deal with the semantic aspect (meanings) of information, looking for ``”intelligent''” management of the information available on the (Semantic) Web, interoperability has not been an easy task. Solutions exist in abundance, but so does a great deal of confusion and complexity regarding the application and benefits of semantic interoperability….