Proof of concept (POC)

A free trial says "look around". A POC says "here is what we agreed the product must do, so let us see if it does". The goal comes first and it is written down. Without that, a trial ends in a shrug, and a shrug is a "no".

A good plan fits on one page and has six parts: the question, the success criteria, the scope, the time box (dates, not "a few weeks"), the people with one owner per side, and the exit. A real POC costs hours from both teams, so offer one only after discovery has shown the problem and what it is worth.