Methods, systems, and apparatus, including computer programs encoded on computer storage media, for classifying events in a stream computing system using hierarchical analytic models. One of the methods includes receiving, by a stream computing system, data representing the values of one or more data attributes of an event in a stream of events. The values of each of the one or more data attributes are evaluated according to respective attribute-specific and class-specific criteria of a hierarchical analytic model in a predetermined order defined by the model. When a first value of a first data attribute satisfies one or more particular criteria for a first class, the first class of the plurality of classes is assigned to the event.