Modern interactive systems can be incredibly complex, with a variety of screens, menus, widgets, etc. available to the user. Due to this, modelling these interactive systems can also be incredibly complex and while there are techniques to help overcome this, it can often lead to radically different models depending on the modeller. This thesis explores the use of two design patterns created in order to help simplify modelling interactive systems. In the process of doing this, we first explore µ-Charts and its semantics, which are defined in Z, in order to understand its capabilities. We then discover a feature we name the Return feature, which we break down into two parts, Return Home and Return Back, and create patterns in order to concisely model them. Finally, we test these patterns and evaluate the tools we used to create the µ-charts, translate them into their Z semantics and test them.