The present invention provides methods, systems and apparatus for detecting unknown scenarios in a data processing system. An example method includes the steps of: providing known scenario data describing one or more known scenarios in a database; creating element data depending on the known scenario data to form a set of elements, wherein each element is related to at least an actor and the behaviour of the actor; computing subsets of elements by combining at least some of the elements of the set in dependence on their corresponding behaviour; creating new scenario data related to new scenarios depending on the subsets of elements; and comparing the known scenario data with the new scenario data in order to identify the unknown scenarios.