Barry Boehm was a visionary and his research and conclusions laid the foundation of methods (for eg. XP) to build software efficiently. One of his many seminal works is the law that he proved (with data) -
The cost of finding and fixing a defect grows exponentially with time
Some of the many practices that engineers follow today address the effects of the law -
- Pair programming
- Continous integration and continuous delivery
- Automated functional tests