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» Requirements from Industry
» Vision of the Semantic Web
» Service Oriented Architecture
» Semantic Web Services
» How to enable Semantic Web Services
» Market Expectations - Roadmap
SOA is today the new paradigm for future development of IT systems in the most business enterprises, e.g. banking, public health, B2B, public government, etc. The most common way of implementing SOA is to base the development on the Web Service standards, i.e. SOAP, WSDL and UDDI. Business processes are operations that constitute the most critical assets of an enterprise. If we use the Web Service Technology to handle those and other enterprise assets, e.g. business data and documents, we then have a state of art SOA system.
SOA will make the enterprise systems more agile and meet most of the current and future challenges faced by enterprises. The most critical challenges are:
- Reducing operational costs
- Creating an IT infrastructure that is flexible and may be changed with minimal costs
- Making the infrastructure capable to combine services across lines of business and distribute them over many evolving communication channels, e.g. fixed, mobile, wireless and broadband networks.
- Minimize the time to market for new aggregated services
In many ways will SOA open up for an evolution toward the "real-time business and enterprise". However, to make them true real-time, it is necessary to add semantics to the service description. This will make it possible to create services automatically. The outcome of this is a system that often is termed Semantic Web Service or "Semantic SOA" if it is applied on business processes in an enterprise.
The science of describing services semantically, registering and finding them, integrate them with a set of other registered services and execute the set automatically in an ordered flow, is called Semantic Web Services. This is especially true when the component (atomic) services follow the Web Service standards. This is a science based on both the knowledge about Web Service plus the knowledge about Semantic Web. Semantics are added to the Web Services in form of ontologies. Different types of semantics, e.g. functional, data and QoS?, have different ontologies. By adding service ontology and domain ontology to WSDL , e.g. by using WSMO or another standards, will translate a service from Web Service to Semantic Web Service. The semantically annotated Web Services may be composed to new services with more complex functionality than each of the atomic ones. (see presentation  Web Services and Semantic Web*)
The most known Semantic Web Service initiatives such as ASG/WSMO, SWSI/SWSF and METEOR/WSDL-S have all a service delivery lifecycle that is very similar. They all run through 3 main service process such as Planning (Discovery/Composition), Agreement (Negotiation/Contracting), Enactment (Invocation/Monitoring/Profiling)that encompass the basic functional elements in an SWS Architecture. Since SOA is just a paradigm, it is necessary to standardize it to enable integration of independently developed SOA systems. In that case, OASIS has made a SOA Reference Model that happens to be downwards compatible with ASG. To integrate a new or legacy service in an ASG service platform, the Service Provider need to make Web Service with a proper WSDL description, then describe the service in WSMO, further register this description in a Registry belonging to the ASG platform and finally make a proxy that understand ASG ontology. When clients want to make complicated requests described semantically, the Service Composition will be started by the platform, the proper atomic Web Services selected and then orchestrated and executed to give a response on the request. (see presentation Architecture Elements for a Semantic Web Service Environment*)
One of the main challenges in the development of the SWS technology is to create a proper service ontology and corresponding languages. The next step is the standardization work. The most known initiatives until now are WSMO, SWFS, WSDL-S and OWL-S. All have overlapping features and have partly been developed in parallel. In addition, they all have used W3C as there target standardization body. It is therefore expected that at the end all those initiatives will cooperate to develop one single standard under supervision of W3C. In order to obtain a good foundation for the future Semantic SOA and SWS, several other technologies also needs to be improved, e.g. business standards like OASIS ebXML, Grid and Agent technology. (see presentation Semantic Web Service Initiatives*)
Adaptive Services Grid (ASG) capabilities
The ASG Key Features are achievements on both the technological and business level:
- Seamless integration of heterogeneous external services. Integrated services are augmented with semantic descriptions regarding service functionality and non-functional properties and the envisaged architecture allows an easy discovery and interoperability of integrated services. This reduces the maintenance and modification costs for large numbers of external services and has the potential to ease integration of services and data formats.
- On-demand creation of service compositions. Automated semantic-enabled service composition that allows creation of new services by composing existing services on-demand and at run-time for individual user requests. For this purpose, the semantically described functionality of services is used. ASG lifts the interface to services from a manual to a automatic level, and supports service composition based on automated tools. The adaptive service composition implies a cost reduction in service provision.
- Reliable service provision with assured quality of service. ASG supports the description, negotiation and realisation of non-functional service quality parameters. In cases of service failures or violations of agreed quality parameters, the platform reacts adaptively through re-enactment, re-binding or re-composition activities. The future service world will be based on global and dynamic services, which can be composed to answer the needs of complex service requests. Dynamic service re-enactment, re-binding or re-composition provide alternative solutions for non-reliable services, thus provides the end-customer with a reliable service delivery.
(see presentation Adaptive Services Grid (ASG) Capabilities*)
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