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Sequence Diagram   «Prev 

Applying the Sequence Diagram

A sequence diagram captures the behavior of a single scenario. The diagram shows a number of example objects and the messages that are passed between these objects within the use case.

Building the Sequence Diagram: Two steps


Step 1: Describe the interaction between the actor and the system

2) Draw the timelines downward from each object

3) Draw the events in the conversation between the actor and the system

Describe the interaction between the Customer and Banking System:
c) The customer asks for $45
d) The system responds saying that the denomination requested is invalid and asks for another amount

Draw the events in the conversation between the actor and the system
e) The customer asks for $40

1) For the first event: a) Determine which object/s the system would use to respond and add the object to the diagram.

Step2:Expand the system to include the resources that the system uses to respod to the actor's requests

For the third event a) Determine which objects the system would use to respond and add the object to the diagram
i) What object would know whether or not the customer has the funds to support a $40 withdrawal.