Managers are not confronted with problems that are independent of each other, but with dynamic situations that consist of complex systems of changing problems that interact with each other. I call such situations messes. Problems are extracted from messes by analysis. Managers do not solve problems, they manage messes.

Russell L. Ackoff (1919-2009) American organizational theorist, consultant, management scientist

“The future of operational research is past,” The Journal of the Operational Research Society, Vol 30, pp.93-104. (1979)