Most requirement analysis methods focus on the description of system and data behaviour. The original features of Kaos are the addition of a description of the objectives for the system and its environment, and a description of the agents (human or automated) which have been given responsibility for achieving these objectives. The Kaos language and models, and the implementation support tool Grail are presented, and three industrial applications of Grail are outlined.
Darimont, R., Delor, E., Massonet, P., & van Lamsweerde, A. (1998). Grail/Kaos: a tool for goal-directed requirement analysis. Proceedings ICSE′98 International Conference on Software Engineering, 139-144. https://hdl.handle.net/2078.5/218732