EWS-a case study on access control in workflow systems

EWS is a workflow engine under development with specific requirements for the access control. We study a subset of these requirements, concerning work assignment, lockups and delegation issues. Three other systems-Changengine, FloWare and the Two-Schema Architecture-have been studied with respect to these problems, and we use the insights gained from these studies to give our own solutions to the problems. Changes that are made in the design of the system include new access, nodes, a structure for which access modes to use for which objects, a process document folder, and a delegation relation.