The claimed subject matter provides a system and/or a method that facilitates creating a composite application. A model architecture component can model a business rule utilizing at least one node in a novel hierarchical structure. A run-time engine can automatically create a complex, long-running composite application based at least in part upon the hierarchical node structure such that representative process segments of the application are invoked by the business rule which, in turn, is invoked by internal, externally generated, asynchronous events.