Earliest Finish Time Earliest Finish Time Worst Case Best Case Latest Finish Time Best Case Latest Finish Time Worst Case Duration Activity Activity

In this paper, we present a novel technique for modeling, checking, and enforcing temporal constraints in workkow processes containing conditionally executed activities. Existing workkow time model-ing proposals either do not discriminate between time constraints that apply to disparate execution paths, or they treat every execution path independently. Consequently, superruous time constraint violations may be detected at modeling time, even when each execution path does not violate any constraints. In addition, scheduling connicts during process execution may not be detected for activities that are common to multiple execution paths. Our approach addresses these problems by (partially) unfolding the workkow graph associated with a process that contains conditionally executed activities and, then, incorporating the temporal constraints in the time calculations performed on the unfolded graph.