In the elaboration of RUP you need to test your architecture to see whether it has any potential risks for your requirements or not. For example if you are going to have an application on your production site, that for each request should reply for at most 1 sec. and there could be 100 req/sec. then you need to test your architecture in an environment exactly as what you would have in the production to see the risks(any diffrence could face you to major problems later).
It is not only documentation. When you pass the elaboration you should have fixed the architectural risks.
Does DSDM also suggest this? Or it is just architecture documentation?Any more infos on DSDM and your experiences is welcome.