Resource Controllability of Workflows Under Conditional Uncertainty

An access controlled workflow (ACWF) specifies a set of tasks that have to be executed by authorized users with respect to some partial order in a way that all authorization constraints are satisfied. Recent research focused on weak, strong and dynamic controllability of ACWFs under conditional uncertainty showing that directional consistency is a way to generate any consistent assignment of tasks to users efficiently and without backtracking. This means that during execution we never realize that we would have chosen a different user for some previous task to avoid some constraint violation. However, dynamic controllability of ACWFs also depends on how the components of the ACWF are totally ordered. In this paper, we employ Constraint Networks Under Conditional Uncertainty (CNCUs) to solve this limitation, and provide an encoding from ACWFs into CNCUs to exploit existing controllability checking algorithms for CNCUs. We also address the execution of a controllable ACWF discussing which (possibly different) users are committed for the same tasks depending on what is going on (online planning).