Use Cases and Requirements

[Graham_Labdon]

Hello Everyone

I am capturing requirements and writing use cases to realize these.

A large part of the project has to do with users interacting with a UI so it is easy to identify Actors for the corresponding Use case (eg user presses button A, something happens)

Another part of the project has to do with controlling various hardware components which is where I am getting a little stuck. As an example when running the program must maintain a water tank at a give temperature by turning on (or off) a heating element.
This is clearly a requirement of the system but how does one write a use case for this ? what can I use as an actor?
 

Thanks

Graham

[Transition Technologies]

Hi Graham,

According to UML notation Actors are not only people. In your case lets say:
Actor - Water Tank
Use Case - Turning on/off the heater

For better recognition of non-person Actors I advise to use Alternate Images (so you can clearly see who is a person in your Use Case Model)

[Graham_Labdon]

Thanks!!

[Graham_Labdon]

How can I get all instnaces of an actor to display an alternative image?

Graham

[«Midnight»]

Perhaps using a template package.

I don't know if you can do this retroactively without some kind of surgery on the data (perhaps through a SQL tweak or an XMI edit).

[Krzysztof Swiatkowski]

If you set that actor to have a specific stereotype (eg. hardware) and associate metafile with that stereotype you will get desired behaviour.
That applies if you want all hardware to look the same . Otherwise you need to set image by hand every time.

Template package changes the way actor is created, it means that if you would want to change that image afterwards you would have to do it manually. I would rather use stereotype.

Regards
Kris

[Graham_Labdon]

I could not get it to work with a metafile, but I have achieved the same using a shape script

Thanks