your question maybe relate with how you draw your sequence diagram. is it a big one or different diagram for each use case? if you choose the former, the pre/post condition is not a problem for your operation procedures are all in one diagram. if you draw them in different small diagrams, the pre/post condition means it is drawed in other diagram. you need to link them togethor to express the relationship.
I suggest to keep the sequence diagrams simple. After all, they constitute only 12 points in the exam. Therefore, I would go with your third choice.
William Butler Yeats: All life is a preparation for something that probably will never happen. Unless you make it happen.
Joined: Sep 22, 2003
Thanks for your reply. Yes I agree, it's preferable to keep SD simple....anyway I wonder what would be of my login procedure ? for example if I choose JAAS instead of Form-based-login, should I illustrate my login procedure with a separate sequence diagram ?