I'm making a small business application and I'm wondering what the best interface would be. The application itself is your run-of-the-mill service ticket tracker. There will be forms for searching tickets (with a grid for results), creating a new ticked & viewing an existing ticket, managing some administrative stuff (users, a few classifiers, etc.), inventory management forms...
So what would be the best interface? Initially I thought about MDI (because that's easy to do in .NET), but then I got my hands on Telerik RAD controls and TDI (Tabbed Document Interface) is now easy to do too (and I'm a fan of TDI since I'm a programmer and most IDEs successfully use that). And while searching for similar questions on SO I found some advice that said that TDI and MDI are both clumsy, and you should do an SDI (a separate taskbar window for each open form).
So... what would be the best here?
I must second Michael Todd's suggestion (and the usual Nielsen/Joel Sposky mantra).
Do user testing
Mock up one and the other. Show to a couple of "representative" target users.
Ask them to workflow through each and describe which feels more natural/intuitive/easy.
Also, this may be a naive advice (I have zero Windows coding experience) but couldn't you code something generic/flexible enough to be able to work in both TDI and non-TDI formats?
(think Firefox "New Tab" vs "New Window" as an obvious example)