Requirements on distribution management for service-oriented automation systems

Current process control and automation systems are statically linked and strictly hierarchical, built between a central engineering station, several PLCs and a wide range of I/O devices. If any intended or unintended changes within this system occur, a large amount of configuration has to be changed. This needs to be reduced by (semi-)automatic mechanisms to establish a self-management and self-configuration environment for such systems. Service-oriented Architecture (SOA) is a widely used concept for developing such a flexible and dynamic system, where even topological and hierarchical changes of software and hardware components could take place during run-time, thus without stopping the production process. This paper describes the requirements for a resource description model, which needs to be investigated to determine (along with their Quality of Service) a suitable and maybe optimal distribution via the different resources of a future SOA-based automation system.