• 
  
  Start with high level use cases and drill down to detailed use cases.
  

   

  
  
  
  


• 
  
  Create them iteratively and incrementally
  

   

  
  
  
  


• 
  
  Use a standard template across the project
  

   

  
  
  
  


• 
  
  Think about the actor's tasks
  

   

  
  
  
  


• 
  
  Make sure they fully describe the users activities
  

   

  
  
  
  


• 
  
  Keep detail that should be in Activity or Sequence diagrams out
  

   

  
  
  
  


• 
  
  Document the alternative flows
  

   

  
  
  
  


• 
  
  Avoid analysis paralysis. Keep them simple and know when to stop.
  

   

  
  
  
  


• 
  
  Leave out design elements e.g. UI or technical design. Keep them focused on behaviour of the intended system.
  

   

  
  
  
  


• 
  
  Understand that the difference between traditional functional requirements and use case scenarios is that previously the focus was on describing what the system will do,use cases describe user actions and the system's responses.
  

   

  
  
  
  


• 
  
  Be explicit about the names of Actors and boundary objects.
  

   

  
  
  
  


• 
  
  Pre- and post-conditions should be used only if they are absolutely necessary
  

   

  
  
  
  


• 
  
  Actors don't need to be human,they can be external systems.
  

   

  
  
  
  


• 
  
  A list of Actors can help to find the Use Cases by working out what they will do.
  

   

  
  
  
  


• 
  
  Don?t forget non-functional requirements such as system performance.
  

   

  
  
  
  

Alistair Cockburn's process for creating Use Cases:

1. 
   
   Name the system scope and boundaries
   

    

   
   
   
   


2. 
   
   Brainstorm and list the actors
   

    

   
   
   
   


3. 
   
   Brainstorm and exhaustively list user goals for the system
   

    

   
   
   
   


4. 
   
   Capture the outmost summary use cases to see 'who really cares',check for an 'outmost' use case for each primary actor
   

    

   
   
   
   


5. 
   
   Reconsider and revise summary use cases. Add,subtract or merge goals
   

    

   
   
   
   


6. 
   
   Select one use case to expand
   

    

   
   
   
   


7. 
   
   Capture stakeholder interests,preconditions and guarantees
   

    

   
   
   
   


8. 
   
   Write the main success scenario
   

    

   
   
   
   


9. 
   
   Brainstorm and exhaustively list the extension conditions
   

    

   
   
   
   


10. 
    
    Write he extension handling steps
    

     

    
    
    
    


11. 
    
    Extract complex flows to sub use cases - merge trivial sub use cases
    

     

    
    
    
    


12. 
    
    Iterate and adjust