It's safe to say that event correlation has been a long time in coming - even though it's been around for years. There is a visible upsurge in automated products that remedy the problems inherent in the old, rules-based model for event correlation. Fortunately, the products have also changed. The term event correlation can be confusing given the fact that it is frequently tuned to fit the marketing needs of a given product. It is used in conjunction with terms like alarm suppression, fault resolution, and root cause analysis, which are closely related but somewhat different in meaning.
Event correlation is the process of correlating alarms to isolate the point of failure.
When it's thorough, event correlation may yield root cause analysis - which provides the single identifiable cause of a problem. Mere alarm suppression provides, by comparison, only a partial answer to the problem - reducing the number of alarms generated by a failure so the person trying to fix the problem isn't overrun by alarms that are of less consequence. Automation is increasingly important as correlation products embrace more devices. A few are moving towards the application space. Clearly this is a good thing.