A method is provided for generating a resource function estimate of resource usage by an instance of a processing element configured to consume zero or more input data streams in a stream processing system having a set of available resources that comprises receiving at least one specified performance metric for the zero or more input data streams and a processing power of the set of available resources, wherein one specified performance metric is stream rate; generating a multi-part signature of executable-specific information for the processing element and a multi-part signature of context-specific information for the instance; accessing a database of resource functions to identify a static resource function corresponding to the executable-specific information and a context-dependent resource function corresponding to the context-specific information; combining the static resource function and the context-dependent resource function to form a composite resource function for the instance; and applying the resource function to the at least one specified performance metric and the processing power to generate the resource function estimate of the at least one specified performance metric for processing by the instance.