Petropoulos, FotiosLaporte, GilbertAktas, Emel2023-10-192023-10-192023-12-27Petropoulos F, Laporte G, Aktas E, et al., (2024) Operational research: methods and applications. Journal of the Operational Research Society, Volume 75, Issue 3, 2024, pp. 423-6170160-5682https://doi.org/10.1080/01605682.2023.2253852https://dspace.lib.cranfield.ac.uk/handle/1826/20407Throughout its history, Operational Research has evolved to include methods, models and algorithms that have been applied to a wide range of contexts. This encyclopedic article consists of two main sections: methods and applications. The first summarises the up-to-date knowledge and provides an overview of the state-of-the-art methods and key developments in the various subdomains of the field. The second offers a wide-ranging list of areas where Operational Research has been applied. The article is meant to be read in a nonlinear fashion and used as a point of reference by a diverse pool of readers: academics, researchers, students, and practitioners. The entries within the methods and applications sections are presented in alphabetical order. The authors dedicate this paper to the 2023 Turkey/Syria earthquake victims. We sincerely hope that advances in OR will play a role towards minimising the pain and suffering caused by this and future catastrophes.enAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/reviewencyclopediatheorypracticeprinciplesoptimisationprogrammingsystemssimulationdecision makingmodelsArticle