There is a lot to say about when to use which diagram type when developing a design, and what the role of it should be. The different answers to this are referred to as the design process or design method. This document is not intended to describe a concrete design process. Poseidon for UML can be used for any such process. Instead, in this chapter we will look at the various diagram types and how the corresponding model elements are created or edited in Poseidon. For many of these diagrams, a short example has already been given in the default model Stattauto, which we looked at in Chapter 4.