Agile software development
Agile software development started around the early 90s and at that time Waterfall was still the common methodology that was being used. The concept that time was developing an engine (eg Rolls Royce) was the same as software development. 100 pages of scoping and requirements, start building the software, Quality Assurance and then Deployment. And that method was being used over years, but what was being disregarded was, most of the time, Client or Users are not happy with the output. It seems its not what they wanted but have no choice but to accept it since its the one they approved from the beginning before the development.