In this document, only a limited set of symbols from UML (Unified Modelling Language) is used. Two kinds of diagrams, the Use Case diagram and the class diagram are presented. Again, this is not a complete introduction on UML, only what is needed to read the diagrams in this document.
Figure C-1. Use Case diagram example
Two actors want to interact with each other. Actor 1 performs action 1 towards Actor 2, who performs Action 2 towards Actor 1 and so on. An actor can be someone like a contractor and an action can be something like request catalogue.