Is there a tool for capturing functional landscape?

[gogobongopop]

Hi,

I'm looking for a tool that can capture system functional capability/landscape, and ideally the management of functional design specifications.

Some background:

Functionally, we've broken our system down into a series of:

- Modules (4 in total)

- Functional Areas (about 20)

- Feature Groups (about 600)

- Features (about 1400)

This is currently all managed in a large, complex and pretty difficult to maintain Excel worbook.

Our functional designs are stored in an internally developed 'Document Repostory' (a notes database), but again, it's not the best version system for our documents and doesn't manage different branches of code versions/documents very well.

So, I'm looking for a tool that effectively allows me to define the functional system architecture/capability in whatever kind of hierachy I define. Ideally, I want to be able to start at the Module level, and then drill down into Feature and find the relevant functional design documentation (e.g. a UID or Use Case)

I've struggled to find anything that might allow me to do this and have resigned to the fact that I might need to develop somthing myself; however I'm hoping you can help!

What do you use to manage these kind of things?

Thanks!