In our third installment on UML we'll show you how to use sequence diagrams as a tool in your application development and an understanding of object interaction.

The UML sequence diagram is based on the nouns in the user storydescription, and illustrates the dynamic interaction between theparticipants in the user stories.

Figure 2 shows aparticular scenario, described using a UML sequence diagram. When anew heart rate is detected from the patient's pick-up, that rate isoutputted to the display; depending on the rate, ...