The present invention relates to a method for processing of start conditions of activities within a process model processable by a Workflow Management System (WFMS); said process model comprises activities being nodes of an graph and directed control connectors defining a potential control flow. The method evaluates, if a target-activity may be started, by evaluating the truth-value of a start-condition once the truth-values of all incoming control-connectors of said target-activity have been posted. A further timed-evaluation-step evaluates, if at least a first one of said incoming control-connectors is associated with a time-interval, and if said time-interval has been met. In the affirmative case said timed-evaluation-step continues the processing to start said target-activity even if not all truth-values of said incoming control-connectors have been posted yet under the condition, that the truth-value of said first incoming control-connector has been posted and that said truth-value evaluates to TRUE.