Operations research

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Operations research (N America) or Operational research (UK/Europe) "is a scientific method of providing executive departments with a quantitative basis for decisions regarding the operations under their control."[1] Other names for it include:

  • Operational analysis (UK Ministry of Defence from 1962)[2]
  • Quantitative management[3]

"The historical development of Operational Research (OR) is traditionally seen as the succession of several phases: the “heroic times” of the Second World War, the “Golden Age” between the fifties and the sixties during which major theoretical achievements were accompanied by a widespread diffusion of OR techniques in private and public organisations, a “crisis” followed by a “decline” starting with the late sixties, a phase during which OR groups in firms progressively disappeared while academia became less and less concerned with the applicability of the techniques developed."[4]. In the current phase, the increase in computing power coupled with the birth of related techniques like business intelligence (BI) and business analytics are leading a resurgence of OR.[5]

Model of Operation research study, based on Stafford Beer (1959).[6]

Contents

[edit] Overview

The terms operations research and management science are often used synonymously.[citation needed] When a distinction is drawn, management science generally implies a closer relationship to the problems of business management.[citation needed] The field of operations research is closely related to Industrial engineering.[citation needed] Industrial engineers typically consider Operations Research (OR) techniques to be a major part of their toolset.

Some of the primary tools used by operations researchers are statistics, optimization, probability theory, queuing theory, game theory, graph theory, decision analysis, mathematical modeling and simulation. Because of the computational nature of these fields, OR also has ties to computer science, and operations researchers use both custom-written and off-the-shelf software.

Operations research is distinguished by its frequent use to examine an entire management information system, rather than concentrating only on specific elements (though this is often done as well). An operations researcher faced with a new problem is expected to determine which techniques are most appropriate given the nature of the system, the goals for improvement, and constraints on time and computing power. For this and other reasons, the human element of OR is vital. Like any other tools, OR techniques cannot solve problems by themselves.

[edit] History

Some say that Charles Babbage (1791-1871) is the "father of operations research" because his research into the cost of transportation and sorting of mail led to England's universal "Penny Post" in 1840, and studies into the dynamical behaviour of railway vehicles in defence of the GWR's broad gauge.[7] The modern field of operations research arose during World War II.

Modern operations research originated at the Bawdsey Research Station in the UK in 1937 and was the result of an initiative of the station's superintendent, A. P. Rowe. Rowe conceived the idea as a means to analyse and improve the working of the UK's early warning radar system, Chain Home (CH). Initially, he analyzed the operating of the radar equipment and its communication networks, expanding later to include the operating personnel's behaviour. This revealed unappreciated limitations of the CH network and allowed remedial action to be taken. [3]

Patrick Blackett.

Scientists in the United Kingdom including Patrick Blackett, Cecil Gordon, C. H. Waddington, Owen Wansbrough-Jones, Frank Yates, Jacob Bronowski and Freeman Dyson, and in the United States with George Dantzig looked for ways to make better decisions in such areas as logistics and training schedules. After the war it began to be applied to similar problems in industry.

[edit] Second World War

During the Second World War close to 1,000 men and women in Britain were engaged in operational research. About 200 operational research boffins worked for the British Army.[8]

Patrick Blackett worked for several different organizations during the war. Early in the war while working for the Royal Aircraft Establishment (RAE) he set up a team known as the "Circus" which helped to reduce the number of anti-aircraft artillery rounds needed to shoot down an enemy aircraft from an average of over 20,000 at the start of the Battle of Britain to 4,000 in 1941[9]

In 1941 Blackett moved from the RAE to the Navy, first to the Royal Navy's Coastal Command, in 1941 and then early in 1942 to the Admiralty.[10] Blackett's team at Coastal Command's Operational Research Section (CC-ORS), included, two future Nobel prize winners, and many other people who went on to be preeminent in their fields,[11] undertook a number of crucial analyses that aided the war effort. Britain introduced the convoy system to reduce shipping losses, but while the principle of using warships to accompany merchant ships was generally accepted, it was unclear whether it was better for convoys to be small or large. Convoys travel at the speed of the slowest member, so small convoys can travel faster. It was also argued that small convoys would be harder for German U-boats to detect. On the other hand, large convoys could deploy more warships against an attacker. Blackett's staff showed that the losses suffered by convoys depended largely on the number of escort vessels present, rather than on the overall size of the convoy. Their conclusion, therefore, was that a few large convoys are more defensible than many small ones.[12]

While performing an analysis of the methods used by RAF Coastal Command to hunt and destroy submarines, one of the analysts asked what colour the aircraft were. As most of them were from Bomber Command they were painted black for nighttime operations. At the suggestion of CC-ORS a test was run to see if that was the best colour to camouflage the aircraft for daytime operations in the grey North Atlantic skies. Tests showed that aircraft painted white were on average not spotted until they were 20% closer than those painted black. This change indicated that 30% more submarines would be attacked and sunk for the same number of sightings.[13]

Other work by the CC-ORS indicated that on average if the depth at which aerial delivered depth charges (DC's) was changed from 100 feet to 25 feet, the kill ratios would go up. This was because if a U-boat saw an aircraft only shortly before it arrived over the target then at 100 feet the charges would do no damage, and if it saw the aircraft a long way from the target it had time to alter course under water so the chances of it being within the 20 feet kill zone of the charges was small. It was more efficient to attack those submarines close to the surface who's location was known than those at a greater depth who's position could only be guessed. Before the change from 100 feet to 25 feet 1% of submerged U-boats were sunk and 14% damaged, after the change 7% were sunk and 11% damaged (if caught on the surface the numbers were 11% sunk and 15% damaged). Blackett observed "there can be few cases where such a great operational gain had been obtained by such a small and simple change of tactics[14]

Bomber Command's Operational Research Section (BC-ORS), analysed a report of a survey carried out by RAF Bomber Command.[citation needed] For the survey, Bomber Command inspected all bombers returning from bombing raids over Germany over a particular period. All damage inflicted by German air defenses was noted and the recommendation was given that armour be added in the most heavily damaged areas. Their suggestion to remove some of the crew so that an aircraft loss would result in fewer personnel loss was rejected by RAF command. Blackett's team instead made the surprising and counter-intuitive recommendation that the armour be placed in the areas which were completely untouched by damage in the bombers which returned. They reasoned that the survey was biased, since it only included aircraft that returned to Britain. The untouched areas of returning aircraft were probably vital areas, which, if hit, would result in the loss of the aircraft.[citation needed]

Map of Kammhuber Line

When Germany organised its air defences into the Kammhuber Line, it was realised that if the RAF bombers were to fly in a bomber stream they could overwhelm the night fighters who flew in individual cells directed to their targets by ground controllers. It was then a matter of calculating the statistical loss from collisions against the statistical loss from night fighters to calculate how close the bombers should fly to minimise RAF losses.[15]

The "exchange rate" ratio of output to input was a characteristic feature of operations research. By comparing the number of flying hours put in by Allied aircraft to the number of U-boat sightings in a given area, it was possible to redistribute aircraft to more productive patrol areas. Comparison of exchange rates established "effectiveness ratios" useful in planning. The ratio of 60 mines laid per ship sunk was common to several campaigns: German mines in British ports, British mines on German routes, and United States mines in Japanese routes.[16]

Operations research doubled the on-target bomb rate of B-29s bombing Japan from the Marianas Islands by increasing the training ratio from 4 to 10 percent of flying hours; revealed that wolf-packs of three United States submarines were the most effective number to enable all members of the pack to engage targets discovered on their individual patrol stations; revealed that glossy enamel paint was more effective camouflage for night fighters than traditional dull camouflage paint finish, and the smooth paint finish increased airspeed by reducing skin friction.[16]

On land, the operational research sections of the Army Operational Research Group (AORG) of the Ministry of Supply (MoS) were landed in Normandy in 1944, and they followed British forces in the advance across Europe. They analysed, among other topics, the effectiveness of artillery, aerial bombing, and anti-tank shooting.

[edit] After World War II

From 1962, military operational research in the United Kingdom became known as "operational analysis" (OA) within the UK Ministry of Defence,[2] where OR stands for "Operational Requirement". With expanded techniques and growing awareness, military OR or OA was no longer limited to only operations, but was extended to encompass equipment procurement, training, logistics and infrastructure.

[edit] Scope of operations research

Examples of applications in which operations research is currently used include:

  • critical path analysis or project planning: identifying those processes in a complex project which affect the overall duration of the project
  • designing the layout of a factory for efficient flow of materials
  • constructing a telecommunications network at low cost while still guaranteeing quality of service (QoS) or Quality of Experience (QoE) if particular connections become very busy or get damaged
  • road traffic management and 'one way' street allocations i.e. allocation problems.
  • determining the routes of school buses (or city buses) so that as few buses are needed as possible
  • designing the layout of a computer chip to reduce manufacturing time (therefore reducing cost)
  • managing the flow of raw materials and products in a supply chain based on uncertain demand for the finished products
  • efficient messaging and customer response tactics
  • robotizing or automating human-driven operations processes
  • globalizing operations processes in order to take advantage of cheaper materials, labor, land or other productivity inputs
  • managing freight transportation and delivery systems (Examples: LTL Shipping, intermodal freight transport)
  • scheduling:
    • personnel staffing
    • manufacturing steps
    • project tasks
    • network data traffic: these are known as queueing models or queueing systems.
    • sports events and their television coverage
  • blending of raw materials in oil refineries
  • determining optimal prices, in many retail and B2B settings, within the disciplines of pricing science

Operations research is also used extensively in government where evidence-based policy is used.

[edit] Societies and journals

Societies

The International Federation of Operational Research Societies[17] is an umbrella organization for operations research societies worldwide. Significant among these are:

  • Institute for Operations Research and the Management Sciences (INFORMS)[18]
  • The Operational Research Society.[19]
  • EURO is the association of European Operational Research Societies.[20]
  • CORS is the Canadian Operational Research Society.[21]
  • ASOR is the Australian Society for Operations Research.[22]
  • MORS is the Military Operations Research Society[23]: based in the United States since 1966 with the objective of enhancing the quality and usefulness of military operations research analysis in support of defense decisions. (MORS)[24]
  • ORSNZ is the Operations Research Society of New Zealand.[25]
  • ORSP is the Operations Research Society of the Philippines[26]
  • ORSI the Operational Research Society of India,[27] and
  • ORSSA the Operations Research Society of South Africa.[28]

Other important Operations Research organizations are:

In 2004 INFORMS began an initiative to market the OR profession better, including a website entitled The Science of Better[31] which provides an introduction to OR and examples of successful applications of OR to industrial problems.

Journals

INFORMS publishes twelve scholarly journals about operations research, including the top two journals in their class, according to 2005 Journal Citation Reports.[32] They are:

Other journals
  • 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.[35]
  • Journal of the Operational Research Society (JORS): an official journal of The OR Society;[36]
  • Journal of Simulation (JOS): an official journal of The OR Society;[37]
  • Military Operations Research (MOR): published by the Military Operations Research Society;
  • Opsearch: official journal of the Operational Research Society of India;
  • OR Insight: a quarterly journal of The OR Society;[38]
  • TOP: the official journal of the Spanish Society of Statistics and Operations Research.[39]

[edit] See also

[edit] Notes

Text document with red question mark.svg
 This article includes a list of references, related reading or external links, but its sources remain unclear because it lacks inline citations. Please improve this article by introducing more precise citations where appropriate. (June 2009)
  1. ^ "Operational Research in the British Army 1939-1945, October 1947, Report C67/3/4/48, UK National Archives file WO291/1301
    Quoted on the dust-jacket of: Morse, Philip M, and Kimball, George E, Methods of Operations Research, 1st Edition Revised, pub MIT Press & J Wiley, 5th printing, 1954.
  2. ^ a b UK National Archives Catalogue for WO291 lists a War Office organisation called Army Operational Research Group (AORG) that existed from 1946 to 1962. "In January 1962 the name was changed to Army Operational Research Establishment (AORE). Following the creation of a unified Ministry of Defence, a tri-service operational research organisation was established: the Defence Operational Research Establishment (DOAE) which was formed in 1965, and it absorbed the Army Operational Research Establishment based at West Byfleet."
  3. ^ http://brochure.unisa.ac.za/myunisa/data/subjects/Quantitative%20Management.pdf
  4. ^ Boussou, Denis, Questioning the history of operational in order to prepare its future http://hal.ccsd.cnrs.fr/docs/00/02/86/41/PDF/cahierLamsade196.pdf
  5. ^ http://analyticsmagazine.com/
  6. ^ Stafford Beer (1959). Cybernetic and Management. English Universities Press.
  7. ^ M.S. Sodhi, "What about the 'O' in O.R.?" OR/MS Today, December, 2007, p. 12, http://www.lionhrtpub.com/orms/orms-12-07/frqed.html
  8. ^ Kirby, [http://books.google.co.uk/books?id=DWITTpkFPEAC&lpg=PA141&pg=PA117 p. 117
  9. ^ Kirby, [http://books.google.co.uk/books?id=DWITTpkFPEAC&lpg=PA141&pg=PA94 pp. 91-94
  10. ^ Kirby, p. 96,109
  11. ^ Kirby, p. 96
  12. ^ "Numbers are Essential": Victory in the North Atlantic Reconsidered, March-May 1943
  13. ^ Kirby, p. 101
  14. ^ (Kirby, pp. 102,103)
  15. ^ [1]
  16. ^ a b Milkman, Raymond H. (May 1968). Operations Research in World War II. United States Naval Institute Proceedings. 
  17. ^ IFORS
  18. ^ INFORMS
  19. ^ The OR Society
  20. ^ EURO
  21. ^ CORS
  22. ^ ASOR
  23. ^ MORS
  24. ^ [2]
  25. ^ ORSNZ
  26. ^ ORSP
  27. ^ ORSI
  28. ^ ORSSA
  29. ^ SISO
  30. ^ I/ITSEC
  31. ^ The Science of Better
  32. ^ INFORMS Journals
  33. ^ Decision Analysis
  34. ^ INFORMS Transactions on Education
  35. ^ JDMS
  36. ^ The OR Society;
  37. ^ The OR Society;
  38. ^ The OR Society;
  39. ^ TOP

[edit] References

  • Kirby, M. W. (Operational Research Society (Great Britain)). Operational Research in War and Peace: The British Experience from the 1930s to 1970, Imperial College Press, 2003. ISBN 1860943667, 9781860943669

[edit] Further reading

  • C. West Churchman, Russell L. Ackoff & E. L. Arnoff, Introduction to Operations Research, New York: J. Wiley and Sons, 1957
  • Joseph G. Ecker & Michael Kupferschmid, Introduction to Operations Research, Krieger Publishing Co.
  • Frederick S. Hillier & Gerald J. Lieberman, Introduction to Operations Research, McGraw-Hill: Boston MA; 8th. (International) Edition, 2005
  • Maurice W. Kirby, Operational Research in War and Peace, Imperial College Press, London, 2003
  • Michael Pidd, Tools for Thinking: Modelling in Management Science, J. Wiley & Sons Ltd., Chichester; 2nd. Edition, 2003
  • Hamdy A. Taha, Operations Research: An Introduction, Prentice Hall; 8th. Edition, 2006
  • Wayne Winston, Operations Research: Applications and Algorithms, Duxbury Press; 4th. Edition, 2003

[edit] External links

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