Development strategy of user navigation systems and GUI applications

GUIs (Graphical User Interfaces) have been developed to make applications easier to use. However, effective methods to support the development process for GUI-based applications are highly required as the applications have become increasingly complex. As the supporting methods, we propose a representation technique to suitably describe the structure of an application using Petri nets. Our technique supports all development activities of GUI-based applications during the analysis, design and implementation stage. On the other hand, concise explanations are indispensible to easily use complex applications and to help achieve user's intended actions. In this paper, we also present a method which is to navigate how to use applications for a user by changing messages depending on the present state of the application based on Petri nets.