Correctness of Work ows in the Presence of Concurrency

Work ow processes are long duration activities and therefore it is not possible to apply the well accepted correctness techniques of transactions directly to work ow systems In this paper we rst mention the correctness problems of work ow systems and then exploit the available seman tics in work ow speci cation in the form of data and serial control ow dependencies to de ne isolation units We show that isolation units in a work ow can be identi ed automat ically i e without human intervention from the work ow de nition We then propose a technique to provide for the correctness of concurrently executing work ows on the ba sis of isolation units The technique is general enough to handle the correctness of hierarchically structured work ows consisting of compound tasks