SOA is a fundamentally new approach to software development. Instead of designing individual programs that perform hundreds of functions, the SOA concept is to design individual functions that can be blended to provide hundreds of different services offering unprecedented flexibility and agility at lower cost. Despite its potential to bridge organizational, service, platform and network divides, challenges of interoperability persists. "SOA is seen as a solution to the needs of businesses that have to become more agile and flexible in order to change with the times and increase their efficiency," explains Rainer Ruggaber at SAP Research in Germany, one of the leading developers of SOA solutions. "That requires interoperability with partners. However, it is essential for businesses to understand the benefits of interoperability, define their business models around it and have a justification for wanting it." Interoperability therefore cannot be addressed solely on the technological level. Ruggaber is leading a large international project dedicated to tackling interoperability. The IST-funded ATHENA project, involving research, technological and industrial partners, is developing solutions to the various interoperability challenges that companies face at the data, services, processing and business levels. To deal with data interoperability, ATHENA is working with semantics, particularly semantic data transformation as a way to translate information stored in different formats and systems between different enterprises. In the services area, it is focusing on model-driven SOA to solve the problem of running different applications on different architectures, such as Web services, Grids or P2P. At the process level the ATHENA partners are employing what they call a 'process abstraction concept' to resolve one of the main dilemmas of companies looking to establish automated cross-organisational processes. To make a product supply chain more efficient, for example, companies have to support information sharing between their corporate applications. This requires their internal systems to be interconnected. However, at the same time confidential information must remain hidden - a situation that is seen by many companies as a trade-off between efficiency and security. "Though this concept is not new, the value of our solutions revolve around the creation of an integrated but secure environment. It means that my internal processes are linked to my public processes which in turn are connected to your public processes and to your internal ones but where outside access to the private processes of both sides is restricted," explains Ruggaber. One pilot for EADS CCR, an ATHENA partner, has been developed to resolve collaboration problems with the European aircraft manufacturer's suppliers over the design of aircraft components. Other ATHENA pilots are aimed at automating and improving the efficiency of supply chain processes in the automotive sector, improving ordering procedures between retailers and manufacturers in the furniture sector and prioritising and automating processes in the telecoms equipment industry. Other areas where the interoperability challenge is being addressed is healthcare and risk management. The SODIUM project, for example, has developed two prototype systems dealing with risk management and healthcare using a standards-based approach to discovering, composing and executing heterogeneous web, peer-to-peer and grid services. It is conducting trials in Norway and Romania. "SODIUM is providing solutions on top of existing standards to create a unified way to discover and compose heterogeneous services," explains the project's scientific coordinator Aphrodite Tsalgatidou. "The main challenge for us is to achieve syntactic and semantic interoperability." The system allows services to be compiled for different architectures and service models. "In crisis management, for example, emergency services have to use a variety of services some of which will be P2P, others will be Web based and others will be Grid based. All of them have to work together," says Tsalgatidou. Risk and crisis management is undoubtedly one area where interoperability is paramount. The ORCHESTRA project is also focusing on this important area, developing a standards-based open SOA to overcome the procedural, technological and communications obstacles that can hinder efficient risk management. "Our architecture will allow interoperable risk management services to be created to overcome the barriers between different actors who use different procedures, databases, systems and languages," explains José Esteban, the project coordinator. "The standards-based approach aims to ensure compatibility between systems, databases and services including those that are already in use by different public administrations across Europe." Standards will undoubtedly play an important role in ensuring the interoperability of SOA solutions. SODIUM, for one, believes its work will improve upon existing standards, while ATHENA partners are also active in several standards bodies. "Without a shadow of a doubt, Service Oriented Architectures will be used widely in the future," predicts Ruggaber. However, "How soon seamless interoperability will occur is still under debate," he adds.