This is a question related to Business Analysis and project lifecycle not specifically testing, so please bear with me.

I have worked as a business analyst for both suppliers & clients over the years and have frequently been involved in User Acceptance Testing. In all projects I have worked on, UAT has been carried out against (and derived from) the customer's requirements spec - provided it has been kept up to date.

However I now have a supplier that expects my client to review & sign off their supplier design specification and use that as the contractual measure of compliance. In my view this is a risky thing to do as it introduces a layer of interpretation of the original requirements, with ambiguities that may be missed during the client's review of the design spec.

Any comments on the rights & wrongs of doing this? Has anyone had to deal with a supplier who insists on this approach? How was this managed to ensure quality?

Thanks in advance for your help.

Lindsay