Events occur as external perturbations across the boundary of the enterprise, or are generated internally.  An event can occur as the result of timing or as the result of some condition becoming true.  Externally generated events can be solicited, and therefore expected, or predictable to an extent (e.g. sales, stimulated by marketing campaigns). Unexpected events are things like typhoons, stock market movements, or the appearance of new technology.  Though unexpected in the sense of being out of control of the enterprise, they can in many ways be anticipated and provided for with contingency plans.

Figure 6

An event initiates a flow of material, information, etc., and it takes an event to initiate an identifiable business situation.  An event is generated by a role being played by an individual or internal or external organization.  Events trigger processes within the enterprise.  A common feature of events is that they are time constrained, starting and stopping at discrete times, or ranges of times.  A key purpose of the information resource of the enterprise is to record the sensing of events as they occur.