—The scale, heterogeneity and dynamism of Grid applications and environments require Grid applications to be self-managing or autonomic. This paper presents the Accord autonomic services architecture that addresses this requirement. Accord enables service and application behaviors and their interactions to be dynamically specified and adapted using high-level rules, based on current application requirements, state and execution context. The design, implementation and evaluation of Accord are presented. An autonomic data streaming application is used to illustrate the self-managing behaviors enabled by Accord.