Introduction to #OperationsResearch by #WestChurchman #RussellAckoff #LeonardArnoff was published 1957. https://archive.org/details/introductiontoo00chur/page/n7/mode/2up
Then in proposing #SystemsThinking, look forward by 22 years, in a presentation and paper to the Operations Research Society.
Ackoff, Russell L. 1979. “The Future of Operational Research Is Past.” _Journal of the Operational Research Society_ 30 (2): 93–104. https://doi.org/10.1057/jors.1979.22.
(Thanks for pointing out the archived source,
@cyetain ).