1. A method for operating a workflow system wherein the workflow comprises a given sequence of activities, comprising: automatically identifying a pair of a primary activity and an associated preparation activity required to be done before executing the primary activity; navigating through a process template of underlying workflow, and calculating the probability at a node of the process template that said primary activity will be reached for a current process instance; and pre-executing said preparation activity in parallel to said given sequence of activities if said probability exceeds a predetermined threshold.