When architecting a system, developing visual models of the architecture can be quite helpful as such models provide an excellent high-level picture of the system, its Components and their relationships. Specifically, you may find it useful to develop these three Unified Modeling Language (UML) diagrams:

• Layer map (represented as a class diagram using packages) that describes the upper-level layers of the architecture
• Deployment diagram (represented by a deployment diagram) that outlines the expected network topology
• Key Abstractions diagram (represented by a class diagram) that shows the key abstractions/components and important relationships among them

For more information on visual modeling, see Guideline: Using Visual Modeling.