Patterns for a log-based strengthening of declarative compliance models

LTL-based declarative process models are very effective when modelling loosely structured processes or working in environments with a lot of variability. A process model is represented by a set of constraints that must be satisfied during the process execution. An important application of such models is compliance checking: a process model defines then the boundaries in which a system/organisation may work, and the actual behaviour of the system, recorded in an event log, can be checked on its compliance to the given model. A compliance model is often a general one, e.g., applicable for a whole branch of industry, and some constraints used there may be irrelevant for a company in question: for example, a constraint related to property assessment regulations will be irrelevant for a rental agency that does not execute property assessment at all. In this paper, we take the compliance model and the information about past executions of the process instances registered in an event log and, by using a set of patterns, we check which constraints of the compliance model are irrelevant (vacuously satisfied) with respect to the event log. Our compliance patterns are inspired by vacuity detection techniques working on a single trace. However, here we take all the knowledge available in the log into consideration.