As discussed in the Workflows and APIs breakaway session, here is the paper on Workflow patterns: van der Aalst, ter Hofsted, Kiepuszewski and Barros, Distributed and Parallel Databases, Volume 14, Number 1, 5-51: Workflow Patterns PDF available at: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.90.1538&rep=rep1&type=pdf