If an activity describes something happening over time, an Event is something that happens at a single point in time.

An event is something that happens, either within the organization, under its control (an Internal Event), or out in the world, outside its control (an External Event). An Event causes Activities to be performed.

For example, External Events might be a particular customer’s decision to buy a particular kind of suit, or the arrival of a shipment of towels. As shown in Figure 7-9, an Event may be the cause of one or more Triggers, each of which must in turn be the cause of one or more Activities, such as processing that sale or receiving that shipment. For example, an Event might be a customer’s decision on June 18, 2007 ...

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