Triggers

• The workflow system cannot force things to happen

in reality:

– The arrival of an electronic message (EDI) which is

needed to execute a task.

– A resource which starts to work on a case.

– The arrival of a paper document.

– A phone call to confirm a purchase order.

• A workflow system is a reactive system, i.e. it is

triggered by the environment.

• Some tasks require a trigger.