The organization (a bank) I am working for is currently working with a vendor on a complex application, which adopts Agile approach. The vendor claims they do not have functional spec or the same sort of documentation since they use Agile Approach. There is a BRD generated from the bank, but it is at a highier level without solution details. Without the solution details documented any where, as a BA/QA on this project, I am not clear how the testing should be performed, given that product owners do not have time to actually test and do not know the details either.

Thanks in advance! 

Thanks Kimbo for your reply!

There is no User Story, other than high level BRD. It turned out that some test cases were created for business owners to execute and provide feedback, but the test cases were modified to align to what the vendor delivered for that cycle. Although the major functionalities are fulfilled, business does not have much to say on the flows, since we want the vendor to work on critical deliverables.

I do not feel vendor's approach speeds up the development cycle. If they simply have the wireframes/mockups and certain functional specs just for that cycle while they develop or even before they develop, we do not have to wait until the codes are developed and checked-in to testing environment, in order to give them the feedback.  

Kimbo, thanks again for your reply and your suggestion!

My feeling is the same as yours. Hopefully things will work out.

My understading of Agile documentation is "just enough", not "no document at all". Please correct if I am wrong.

I personally feel the hybrid approach might work better for most projects. "Agile" might easily be used as an excuse for some projects if things do not go well.