Querying event logs: Discovering non-events in event logs

Nowadays companies are more complex than before. Processes are linked together and a lot of data stream through organizations. Every second hundreds or even thousands of events occur. Accordingly it becomes a very challenging job to find meaningful events, patterns or non-events. Continuous query languages can support end users to manage this infinite stream of events and aid to discover significant events. Particularly the search for expected events that didn´t take place is important to prevent them of going by unnoticed. Finding these so-called non-events is a tremendous challenge for organizations because these events aren´t registered. This paper investigates available tools and compares how these tools can be used to find such non-events with two different continuous query languages. From now on, even things that didn´t happen, won´t escape being noticed.