Most of the time, in my opinion, and from my experience, is that non-functional requirements are never defined from their business analysts, and it's the same i

Most of the time, in my opinion, and from my experience, is that non-functional requirements are never defined from their business analysts, and it's the same in many places. A lot of places won't define performance requirements, as it's not their forethought to do so. They care about functional requirements, and if it meets those, then in their mind, their work is done. I've worked in several places (big names, too), that don't define non-functional stuff until after their beta is shipped and people start complaining.