Use case diagram... help

Im trying to learn the fine art of designing applications the right way. I have very good knowledge of vb.net and OO programming. Now I am trying to learn UML and design. I have limited knowledge already, but I want to be better. Therefor I started my own project (asp.net), which is an epurchasing application. The requirements are that of any other epurchasing application, so I won't list them (Orders, stock, customer management, authentication etc)

When I first started to think about the usecase diagram(s), I found these possible actors

* Customer (the one who is buying)

* Administrator (the one who manages customers and orders)

* Supplier (the one who manages the stock and the parts therein)


Im not sure if there are any more actors... it will be possible as a requirement to replace the supplier from a "user" to a "system", meaning all stock management will be handled automatically (with webservices).

And then there was the tedious process of fining usecases. I found quite a few of them quickly, but some where harder (like how to handle authentication). I am sure there are more usecases than the ones I have found, aspecially in the stock area...


I am also not sure wether or not I should have made 3 separate diagrams (one for order, one for customer management and one for stock management), what do you think?

Also, what about interfaces (lollipops)? Can you find any usefulness using them here? I couldn't.

If someone has the strength to download my visio chart and make some comments on it, I would be really happy! I have noticed that the only way to ever learn this is practice, practice... I have read many books on UML, design patterns and OO, but without practical experience, it is a lost cause...

Feel free to edit the diagram, add usecases, make notes whatever!!!!!!!!! I want to learn!



yours
Henrik
ps I couldn't upload the visio file, too big.. ds

No one who knows anything about use cases and use it in your daily work, c'mon guys... :eek:


kind regards
henrik

Hi,
(this is what i remember from 2 years ago at uni!)

I've had a quick look and i would have thought that it would be better to have each actor as a seperate diagram. Putting them all on one make the diagram look a bit busy.
If you do move bits of actors to automated systems remember that you can have systems as actors as well.

Are you going to do a class diagram next?

Nick

Great with an answer, I was afraid I was the only one who used use cases In my work ;)

Yeah it is best to split the diagram into three separate ones...


And yes, a class diagram is the next piece I will produce... I'll evaluate the responses of the use case diagram first.

kind regards
Henrik