Any interaction with the VirtualObservatory: logging in, running a job, receiving results etc. A use case should define the PrimaryActor, the dialogue she/he will have with the system and the result that will be achieved.

I have derived definitions on this site from a number of books (need full details):

• Philippe Kruchten, The Rational Unified Process
• Frank Armour & Granville Miller, Advanced Use Case Modelling
• Alistair Cockburn, Writing Effective Use Cases

-- TonyLinde - 18 Jan 2002

A reasonable www link about use cases is to be found at The Use Case Zone

-- NicholasWalton - 27 Jan 2002