Section 9.3. Applying Participants to a Timing Diagram

9.3. Applying Participants to a Timing Diagram

First, you need to create a timing diagram that incorporates all of the participants involved in the Create a new Regular Blog Account interaction, as shown in Figure 9-4.

The full participant names have been left out of Figure 9-4 to keep the diagram's size manageable, although you could equally have included the full <name>:<type> format for the title of a participant.

Another feature that is missing from Figure 9-4 is the participants that are created and destroyed within the life of the interaction: the :AuthorDetails and :RegularBlogAccountparticipants. Details of these participants have been left out because timing diagrams focus on timing in relation to state changes. Apart from being created and/or destroyed, the :AuthorDetails and :RegularBlogAccount participants do not have any complicated state changes; therefore, they are omitted because they would not add anything of interest to this particular diagram.

During system modeling activities, you will need to decide what should and should not be explicitly placed on a diagram. Ask yourself, "Is this detail important to understanding what I am modeling?" and "Does including this detail make anything clearer?" If the answer is yes to either of these questions, then it's best to include the detail in your diagram; otherwise, leave the additional detail out. This might sound like a fairly crude rule, but it can be extremely effective when you are trying to keep a diagram's clutter to a minimum.

Figure 9-4. The names of the main participants involved in an interaction are written vertically on the lefthand side of a timing diagram