KAOS, is a goal-oriented software requirements capturing approach in requirements engineering. It is a specific Goal modeling method; another is i*. It allows for requirements to be calculated from goal diagrams. KAOS stands for Knowledge Acquisition in automated specification or Keep All Objectives Satisfied.
The University of Oregon and the University of Louvain (Belgium) designed the KAOS methodology in 1990 by Axel van Lamsweerde and others. It is now widely taught worldwide at the university level for capturing software requirements.
References
KAOS (software development) Wikipedia(Text) CC BY-SA