A method is disclosed for modeling and processing an asynchronous functional specification to provide an input to an architecture synthesis engine. The method includes the step of generating an initial task graph from the specification, the task graph having a number of executable tasks. Selected data and control connections are established between respective tasks in accordance with a specified set of rules to define some of the tasks to be deterministic, and other of the tasks to be non-deterministic. Each of the control connections is then marked, to provide an annotated task graph for use as an input to the architecture synthesis engine, the annotated task graph enabling the engine to employ specified scheduling techniques.