On-the-Fly Auditing of Business Processes

Information systems supporting business processes are usually very complex. If we have to ensure that certain business rules are enforced in a business process, it is often easier to design a separate system, called a monitor, that collects the events of the business processes and verifies whether the rules are satisfied or not. This requires a business rule language (BRL) that allows to verify business rules over finite histories. We introduce such a BRL and show that it can express many common types of business rules. We introduce two interesting properties of BRL formulas: the future stability and the past stability. The monitor should be able to verify the business rules over the complete history, which is increasing over time. Therefore we consider abstractions of the history. Actually we generate from a set of business rules a labeled transition system (with countable state space) that can be executed by the monitor if each relevant event of the business process triggers a step in the labeled transition system. As long as the monitor is able to execute a step, the business rules are not violated. We show that for a sublanguage of BRL, we can transform the labeled transition system into a colored Petri net such that verification becomes independent of the history length.