Once the components of the application are decided, the next step is todetail the application workflow. In this stage, you would examine each andevery feature that has been decided upon, and come up with screen flowdiagrams or schematics that clearly delineate the important elements of theinterface, and the relationships between them.
Among the items that should be meditated upon here are:
* The screens required for each function
* The placement of screen elements
* Navigation between screens, and the various points of access of thescreens
* The data captured from the user at each screen, including data types,validation rules and constraints; source and destination containers for thedata; and the data processing logic and business rules applicable at eachstage
The depiction of each of these functions can be aided with a prototype, ifthe budget can support it; this prototype comes in handy to verify that yourassumptions and design decisions work in a real-world environment, and toget real feedback from project managers and client representatives thatthings are proceeding in the right direction. When asking for feedback, itis important to always restrict the discussion to the core issues at hand,in order to avoid the discussion digressing into issues of fonts andbranding rather than navigation and screen layout.
Another good idea, and one that I use often, is to include a top-level flowchart showing the relationships between functions, modules and screens; thedata elements controlled by each; and the interfaces between each. Thisprovides readers and reviewers with a big-picture overview of how theapplication is structured and gives them a reference point to go back to incase they get lost, in much the same way as a site map on a Web site does.