That requirees the customer to have enough know-how to actually make the design review meating meaningful.

Many customers gets so surprised when they are asked all the silly questions - they can't understand that something so simple (their view) can require so much specifications. They see "what should work" but totally forgot "what shouldn't work". They never thing about all the alternatives to consider are:
- what is the battery runs low?
- what if the capture memory gets full because people aren't downloading?
- what if the user can't download?
- what if there is a power failure?
- what if the remote equipment is broken?
- what if user plugs in wrong cables?
- what if it is too dark outside when the equipment is used?
- what if the user is color blind?
- what if there is a power surge?
- ...

In the end, most projects fails because the customer didn't consider what error conditions or misuse that was important to cover. How about a perfect car that runs fast, silent and smooth, but doesn't tell the user when it's about to run out of fuel? What about a vehicle that can't be started if run totally empty (batteries dead or fuel pump can't pump if system have been totally emptied). There are millions of these details that are important that the customer tends to forget. Many times, they think the issues are trivial and can be handled on-the-way. But for the hardware, this tiny, trivial, requirement may be a show-stopper.