Operations research
Management science: In 1967, Stafford Beer characterized the field of management science as "the business use of operations research". Like operational research itself, management science (MS) is an interdisciplinary branch of applied mathematics devoted to optimal decision planning, with strong links with economics, business, engineering, and other sciences. It uses various scientific research-based principles, strategies, and analytical methods including mathematical modeling, statistics and numerical algorithms to improve an organization's ability to enact rational and meaningful management decisions by arriving at optimal or near-optimal solutions to sometimes complex decision problems. Management scientists help businesses to achieve their goals using the scientific methods of operational research.
The management scientist's mandate is to use rational, systematic, science-based techniques to inform and improve decisions of all kinds. Of course, the techniques of management science are not restricted to business applications but may be applied to military, medical, public administration, charitable groups, political groups or community groups.
Management science is concerned with developing and applying models and concepts that may prove useful in helping to illuminate management issues and solve managerial problems, as well as designing and developing new and better models of organizational excellence.
The application of these models within the corporate sector became known as management science.

Related fields: Some of the fields that have considerable overlap with Operations Research and Management Science include:

Applications: Applications are abundant such as in airlines, manufacturing companies, service organizations, military branches, and government. The range of problems and issues to which it has contributed insights and solutions is vast. It includes:

Scheduling (of airlines, trains, buses etc.)
Assignment (assigning crew to flights, trains or buses; employees to projects; commitment and dispatch of power generation facilities)
Facility location (deciding most appropriate location for new facilities such as warehouses; factories or fire station)
Hydraulics & Piping Engineering (managing flow of water from reservoirs)
Health Services (information and supply chain management)
Game Theory (identifying, understanding; developing strategies adopted by companies)
Urban Design
Computer Network Engineering (packet routing; timing; analysis)
Telecom & Data Communication Engineering (packet routing; timing; analysis)

Management is also concerned with so-called soft-operational analysis which concerns methods for strategic planning, strategic decision support, problem structuring methods. 
In dealing with these sorts of challenges, mathematical modeling and simulation may not be appropriate or may not suffice. Therefore, during the past 30 years, a number of non-quantified modeling methods have been developed. These include:

stakeholder based approaches including metagame analysis and drama theory
morphological analysis and various forms of influence diagrams
cognitive mapping
strategic choice
robustness analysis

Societies and journals: 

Societies: The International Federation of Operational Research Societies (IFORS) is an umbrella organization for operational research societies worldwide, representing approximately 50 national societies including those in the US, UK, France, Germany, Italy, Canada, Australia, New Zealand, Philippines, India, Japan and South Africa. For the institutionalization of Operations Research, the foundation of the (IFORS) in 1960 was of decisive importance, which stimulated the foundation of national OR societies in Austria, Switzerland and Germany. IFORS held important international conferences every three years since 1957. The constituent members of IFORS form regional groups, such as that in Europe, the Association of European Operational Research Societies (EURO). Other important operational research organizations are Simulation Interoperability Standards Organization (SISO) and Interservice/Industry Training, Simulation and Education Conference (I/ITSEC)
In 2004, the US-based organization INFORMS began an initiative to market the OR profession better, including a website entitled The Science of Better which provides an introduction to OR and examples of successful applications of OR to industrial problems. This initiative has been adopted by the Operational Research Society in the UK, including a website entitled Learn About OR.

Journals of INFORMS: The Institute for Operations Research and the Management Sciences (INFORMS) publishes thirteen scholarly journals about operations research, including the top two journals in their class, according to 2005 Journal Citation Reports. They are:

Decision Analysis
Information Systems Research
INFORMS Journal on Computing
INFORMS Transactions on Education (an open access journal)
Interfaces
Management Science
Manufacturing & Service Operations Management
Marketing Science
Mathematics of Operations Research
Operations Research
Organization Science
Service Science
Transportation Science

Other journals: These are listed in alphabetical order of their titles.

4OR-A Quarterly Journal of Operations Research: jointly published the Belgian, French and Italian Operations Research Societies (Springer);
Decision Sciences published by Wiley-Blackwell on behalf of the Decision Sciences Institute
European Journal of Operational Research (EJOR): Founded in 1975 and is presently by far the largest operational research journal in the world, with its around 9,000 pages of published papers per year. In 2004, its total number of citations was the second largest amongst Operational Research and Management Science journals;
INFOR Journal: published and sponsored by the Canadian Operational Research Society;
Journal of Defense Modeling and Simulation (JDMS): Applications, Methodology, Technology: a quarterly journal devoted to advancing the science of modeling and simulation as it relates to the military and defense.
Journal of the Operational Research Society (JORS): an official journal of The OR Society; this is the oldest continuously published journal of OR in the world, published by Taylor & Francis;
Military Operations Research (MOR): published by the Military Operations Research Society;
Omega - The International Journal of Management Science;
Operations Research Letters;
Opsearch: official journal of the Operational Research Society of India;
OR Insight: a quarterly journal of The OR Society published by Palgrave;
Pesquisa Operacional, the official journal of the Brazilian Operations Research Society
Production and Operations Management, the official journal of the Production and Operations Management Society
TOP: the official journal of the Spanish Statistics and Operations Research Society.

See also: 

References: 

Further reading: 

Classic books and articles: R. E. Bellman, Dynamic Programming, Princeton University Press, Princeton, 1957
Abraham Charnes, William W. Cooper, Management Models and Industrial Applications of Linear Programming, Volumes I and II, New York, John Wiley & Sons, 1961
Abraham Charnes, William W. Cooper, A. Henderson, An Introduction to Linear Programming, New York, John Wiley & Sons, 1953
C. West Churchman, Russell L. Ackoff & E. L. Arnoff, Introduction to Operations Research, New York: J. Wiley and Sons, 1957
George B. Dantzig, Linear Programming and Extensions, Princeton, Princeton University Press, 1963
Lester K. Ford, Jr., D. Ray Fulkerson, Flows in Networks, Princeton, Princeton University Press, 1962
Jay W. Forrester, Industrial Dynamics, Cambridge, MIT Press, 1961
L. V. Kantorovich, "Mathematical Methods of Organizing and Planning Production" Management Science, 4, 1960, 266–422
Ralph Keeney, Howard Raiffa, Decisions with Multiple Objectives: Preferences and Value Tradeoffs, New York, John Wiley & Sons, 1976
H. W. Kuhn, "The Hungarian Method for the Assignment Problem," Naval Research Logistics Quarterly, 1–2, 1955, 83–97
H. W. Kuhn, A. W. Tucker, "Nonlinear Programming," pp. 481–492 in Proceedings of the Second Berkeley Symposium on Mathematical Statistics and Probability
B. O. Koopman, Search and Screening: General Principles and Historical Applications, New York, Pergamon Press, 1980
Tjalling C. Koopmans, editor, Activity Analysis of Production and Allocation, New York, John Wiley & Sons, 1951
Charles C. Holt, Franco Modigliani, John F. Muth, Herbert A. Simon, Planning Production, Inventories, and Work Force, Englewood Cliffs, NJ, Prentice-Hall, 1960
Philip M. Morse, George E. Kimball, Methods of Operations Research, New York, MIT Press and John Wiley & Sons, 1951
Robert O. Schlaifer, Howard Raiffa, Applied Statistical Decision Theory, Cambridge, Division of Research, Harvard Business School, 1961

Classic textbooks: Taha, Hamdy A., "Operations Research: An Introduction", Pearson, 10th Edition, 2016
Frederick S. Hillier & Gerald J. Lieberman, Introduction to Operations Research, McGraw-Hill: Boston MA; 10th Edition, 2014
Robert J. Thierauf & Richard A. Grosse, "Decision Making Through Operations Research", John Wiley & Sons, INC, 1970
Harvey M. Wagner, Principles of Operations Research, Englewood Cliffs, Prentice-Hall, 1969
Wentzel (Ventsel), E. S. Introduction to Operations Research, Moscow: Soviet Radio Publishing House, 1964.

History: Saul I. Gass, Arjang A. Assad, An Annotated Timeline of Operations Research:  An Informal History. New York, Kluwer Academic Publishers, 2005.
Saul I. Gass (Editor), Arjang A. Assad (Editor), Profiles in Operations Research: Pioneers and Innovators. Springer, 2011
Maurice W. Kirby (Operational Research Society (Great Britain)). Operational Research in War and Peace: The British Experience from the 1930s to 1970, Imperial College Press, 2003.