Improvement of flexibility and interoperability is a usual concern of industrial automation systems developers. Service-oriented architecture is one approach promising improvement of flexibility and interoperability in existing distributed automation systems. However, the intelligent self-managing features cannot be fully achieved by just applying the service-oriented architecture. In order to improve efficiency and reliability of distributed automation systems, the service-oriented architecture is extended in this paper by autonomic service management. The design of the autonomic service manager is provided and some key features such as self-configuration, self-healing and self-optimization are demonstrated. The design of a flexible and interoperable execution environment is also illustrated. Some preliminary tests are completed with a case study.