Dynamic Controllability of Processes without Surprises

Dynamic controllability guarantees that a process control can steer the execution of a business process without violating any temporal constraints although some tasks have uncontrollable durations. However, it has been shown that dynamic controllability may lead to process executions with the undesirable property that tasks have to be started or ended on extremely short notice. Sudden termination forces the agent to immediately terminate the execution of a process task without any prior notice in order to meet some temporal constraints. Semi-dynamic controllability guarantees dynamic controllability and the absence of sudden termination. Here, we show that dynamic controllability may also lead to the problem of sudden start, which forces the immediate start of a process task without prior notice. We formalize all constellations of temporal constraints causing sudden start and sudden termination in a process. We propose a technique to design processes in which activities can be dynamically dispatched without these surprises, i.e., with advance notice, and extend the notion of semi-dynamic controllability by also considering the sudden start. This leads to a sound and complete algorithm for checking the semi-dynamic controllability of time-constrained processes.