I see where you are coming from. I would like to add two points. First, I have rarely seen only one approach to "it works". There are always more than one ways

I see where you are coming from. I would like to add two points. First, I have rarely seen only one approach to "it works". There are always more than one ways to "will it work?". Second, in order to get around the definition of "working" - I encourage people to specify success criteria upfront. Now, even if the definition of success criteria change later - they are all transparent. Everyone involved in the process has accountability and responsibility to oversee the right success criteria, change of success criteria.