Use Cases

A use case is a little piece of functionality the system (the app) has to offer. A flow in a short use case outline can be considered as a SCRUM user story, so they complement each other perfectly.  

Use Case  Solve sudoku
Actor Sudoku player who wants to learn and practice advanced solving techniques
Goal Solve a difficult sudoku puzzle
Basic Flow 
  1. The actor loads a sudoku puzzle by the way of copy and paste
  2. The actor requests the app to apply basic sudoku logic
  3. The actor repeats step 2 until the app gets stuck
  4. The actor applies advanced sudoku techniques to break the puzzle open
  5. The actor repeats step 2, 3 and 4 until the puzzle has been solved
  6. The actor requests the app to check the validity of the solutiion
  7. The app  confirms that the puzzle has been solved properly
Alternative Flows
  • Import puzzle from file
  • Manually set givens and load 

 To clarify a use case you might use prototyping. The following screen shots show how the app has to work.

Situating after loading a puzzle: Situation after applying basic logic: Situation after apply solving technique XY-Wing: Situation after apply solving technique W-Wing followed by again applying basic logic