Whether the machine is up or down is a transient attribute, that is part of implementation. Refining with inheritance .organize classes by using inheritance to share common structure. 638 .when the same association name appears more than once with substantially the same meaning, try to generate the associated classes. Testing access path .trace access path through the object diagram to see if they yield sensible results. Iterating object modeling .a continual iteration .refinement can come after the completion of the dynamic and functional model.
Transaction consists of one of more updates on individual account.
Bank computer into Bank and Central computer into Consortium. Grouping classes into sheets and modules .divide diagrams into sheets of reasonable size.