add site
services
publishers
database
health videos
toolbar
stats
live show
health store
more stuff
JOIN/LOGIN
| advertise add site services publishers database health videos
| | about toolbar stats live show health store more stuff JOIN/LOGIN |
Operation Theatre Equipment, Operation Equipment Exporters, Operation... medicalsurgicals.com | Director of Research Operations: Lisa Cox, MA cpcmed.org | Dorr Institute for Arthritis Research - Hip and Knee Replacement,... dorrarthritisinstitute.or... |
Operations research or operational research is the application of analytical methods and mathematical models to help in improved decision-making. [1] [2] Originating in military efforts before World War II, its techniques have grown to concern problems in a variety of industries [3]. 
[edit] OverviewThe terms operations research and management science are often used synonymously to describe a wide range of problem-solving techniques and methods applied in the pursuit of improved decision-making and efficiency [5]. 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] HistoryAcademic Deins Bouyssou describes the historical development of Operations Research from the 1940s to the 1970s as follows. "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."[6]. Since then, Operations Research has expanded into a set of techniques widely used in industries ranging from petrochemicals to airlines, finance, logistics, and government, moving away from interdisciplinary teams to a focus on the development of mathematical models that can be used to analyze and optimize complex systems[7] [edit] Historical OriginsIn the World War II era, Operations Research was defined as "a scientific method of providing executive departments with a quantitative basis for decisions regarding the operations under their control."[8] Other names for it included operational analysis (UK Ministry of Defence from 1962)[9] and quantitative management[10] 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.[11] 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] 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 WarDuring the Second World War close to 1,000 men and women in Britain were engaged in operational research. About 200 operational research scientists worked for the British Army.[12] 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[13] 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.[14] 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,[15] 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.[16] 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.[17] 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[18] 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]  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.[19] 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.[20] 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.[20] 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 IIFrom 1962, military operational research in the United Kingdom became known as "operational analysis" (OA) within the UK Ministry of Defence, 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 researchExamples of applications in which operations research is currently used include:
Operations research is also used extensively in government where evidence-based policy is used. [edit] Societies and journals
The International Federation of Operational Research Societies[21] is an umbrella organization for operations research societies worldwide, representing societies in the US, [22], UK [23], Europe [24], Canada [25], Australia[26], New Zealand[27], Phillippines[28], India,[29] and South Africa [30]. Other important Operations Research organizations are Simulation Interoperability Standards Organization (SISO) [31] and Interservice/Industry Training, Simulation and Education Conference (I/ITSEC) [32] In 2004 the US-based organization INFORMS began an initiative to market the OR profession better, including a website entitled The Science of Better[33] which provides an introduction to OR and examples of successful applications of OR to industrial problems.
INFORMS publishes twelve scholarly journals about operations research, including the top two journals in their class, according to 2005 Journal Citation Reports.[34] They are:
[edit] See also[edit] Notes
[edit] References
[edit] Further reading
[edit] External links
|
| ↑ top of page ↑ | about thumbshots |
