How to make Quality Assurance and unit tests for a DW/BI project?

Hi,
How to write a Quality Assurance (QA) tests documents for a DW/BI project. Who are involved, what do we need and what are the steps to follow? What do we really have to test?
How do developpers make the unit tests for the ETL process or BI applications? Do they also have to follow or write any documents?
Can you help me to get QA and unit tests document samples for DW/BI projects.

Thank you
(sorry for my bad english)

There is a unit testing tool developed for Microsoft's ETL environment - it's ssisUnit, and it's free on CodePlex. That might help with part of your request...

I am curious, from a best practices perspective, where people lie in terms of formalized testing of DW projects.

I mean, a software project if fairly straightforward (IMHO) from a testing perspective... What about DW? We constantly debate where DEV/unit testing ends and INTG begins, etc. We also tend to focus 90% in the ETL space (probably appropriate)....

Thoughts?

Having worked at multiple clients, I can tell you there is no consistent approach on testing DW applications. In theory, DW's should be held to the same standard as any other software application. I see two general areas of interest in testing DW's. The first you already mentioned, ETL. Source to target transformations should be tested for correctness. This is only possible if you actually maintain source to target mappings. These mappings are the coding specifications for the ETL developers. I've known many a developer that misinterpreted a mapping rule. The second area is reporting. Do the metrics reconcile to the source system(s)? Do the dimensions manage change correctly? If your group is also responsible for the BI Tool then this must also be included in the test plan.

thanks, BoxesAndLines...

Yeah, this seems pretty consistent with what I am seeing....

You may want to have a look at Cindi Howson's BIScorecard.com for an evaluation of OBIEE and other BI products.