Planning usability and functionality

Usability is a basic user requirement and must therefore be a priority in the application design process. Your application must function in such a way that users can learn to use it quickly, perform basic tasks smoothly, and have a pleasant experience using all input methods supported by the application. The UI design must maintain coherence and consistency throughout the application. It is also important that the application reacts well to user interaction and changes in the system (such as screen orientation changes on S60 devices).

Since the UI and functionality of your application largely determine the required Flash Lite version and the application architecture, start the design process by designing the UI and defining the main tasks the user can perform with the application:

• Define the main use cases:

  • What are the common use cases for your application?

  • Can you prioritize the use cases to suit your goals?

  • What kind of functionality do these use cases involve or require? Can the functionality be segmented?

  • How do the use cases and functionality affect the UI? Can you implement them with Flash Lite?

  • Can you divide the UI into components?

• Create wireframes and other UI diagrams to plan the states, views, navigation, and input methods for the application.

  

  Figure: Application UI diagrams

For more information about usability, see section User experience overview in the Design and User Experience Library.

For a design example, see section Defining the Sudokumaster UI and functionality.