I found that some of you made one Class Diagram for the assignment. How can one class diagram illustrate all classes in the application? Where can my EJBs or helper classes be placed? As I know that, there would have three kinds of classes, entity, boundary and control classes. Each kind of them gives its own functionality, e.g. entity class declares the business entity. While I am preparing for the assignment, I found difficult on differentiating the class diagram and the component diagram. Does the class diagram only the business model? or Should I draft more and more class diagrams. Please help!!