[KenWittlief]

In my 22 year career as an engineer I have never been in a meeting where technical decisions were made by the design team voting on options.

There are clear processes and measurement criteria for making engineering decisions that are functions of real system characteristics: cost, complexity of design, modularity, weight, power requirements, size, unknowns that have to be resolved (risk), manufacturability, reliability, repairabilty, resources required...

you can make a matrix with each characteristic across the top, and put each design approach on a row, grading each point on a scale from 1 to 5. The approach with the highest score is the best system.

There is no need to vote, unless two approaches come out exactly equal on the evaluation.

We have done this on FIRST teams - it makes a huge difference in the students attitudes. We can honestly say "I think your idea is awesome, but we are doing something different, for reasons you can clearly see". This goes over much better than a show of hands, and the resulting battered egos.