Operations research (OR) is the application of scientific methods to operational problems. It aims to provide optimal solutions to problems involving complex systems. OR was first developed during World War II to help the British military optimize resources. It has since spread to other fields like industry and transportation. OR uses mathematical models to represent real-world systems. These models allow experimenting with different solutions without impacting the actual system. OR employs techniques like linear programming, queuing theory, and simulation. The OR process involves formulating the problem, constructing a model, deriving and testing solutions, and implementing results. While powerful, OR has limitations such as difficulty modeling intangible factors and incorporating changing data.

1. Operations Research
• Meaning of OR
• Litterally the word operations may be defined as, some
action that we apply to some problems or hypothesis. The
word ‘research’ is an organised process of seeking out
facts about the same.
• Definition
• According to T.L Santy, “OR is the art if giving bad
answers to problems which otherwise have worse
answers”.

2. • CW Churchman defines OR as, ‘operations research is
the appplication of scientific methods, techniques and
tools, to problems involving the operation of a system so
as to provide those in control of the system with optimum
solution to the problem’.

3. History of Operations Research
• The name ‘Operations Research’, came in use from a
military context. During World War II, England undertook a
program known as ‘Research in Military Operaions’. Military
management called on scientist from various disciplines
and organised them into teams to assist in solving strategic
and technical problems relating to defence of the country.
Their mission was to arrive at decisions on optimal
utilisation of scare military resources and to implement
those decisions effectively. This new approach to the
systematic and scientific study of the operations of the
system was called ‘Operations Research’.

4. • Operation Research provides a good intelectual support
to the strategic initiatives of the military commands.
Henceit is said that, ‘OR‘ is the art of winning war without
actually fighting it.
• Because of the success of ‘OR’, on military operations, it
quickly spread to the other feilds also.

5. Features/Characteristics or Nature of OR
• System Orientation
• Inter-Diciplinary team approach
• Scientific approach
• Decision Making
• Optimisation objective
• Mathematical models and quantitative solutions
• Bad answers to the problem
• Use of computers

6. Importance or Functions of ‘OR’
• ‘OR’ provides a tool for scientific analyser.
• ‘OR’ provides solution for various business problems.
• ‘OR’ enables proper development of resources
• ‘OR’ help in minimizing waiting and servicing cost.
• ‘OR’ assist in choosing an optimum strategy.
• ‘OR’ facilitates the process of decision making.

7. Scope or Applications or Uses of ‘OR’
• In defence operations
• In Industry
• In Planning
• In Agriculture
• In Transport

8. Modeling in ‘OR’
• What is Model?
• Models play a very important role in ‘OR’. They are
representations of reality.
• Models provide, descriptions and explanations of the
operations of the system that they represent. By
experimenting on them, we can determine how the
changes in the relevant system will effect it’s perfomance.
• Model in ‘OR’ may be defined as an idealised
representation of a real life system.

9. Properties/Characteristics of a Good Model
• It should be simple
• It should be capable of adjustments with new formulations
without having any significant changes in it’s frame.
• It should contain very few variables.
• A model should not take much time it’s contruction.

10. Advantages of a Model
• It describes problems more concisely
• It provides some logical and systematic approach to the
problem.
• It indicates limitations and scope of the problem
• It tends to make the overall structure of the problem more
comprehensible.
• It facilitates dealing with the problem in it’s entirety.
• It enables the use of high powered mathematical
techniques to analyze the problem

11. Disadvantages of a Model
• Models are only an attempt to undertstand an operation
and should never be considered as absolute in any
sense.
• The validity of any model can only be verified by carrying
on experiments and relevant data charateristics.

12. TYPES OF MODEL
• Iconic model
• Analogue model
• Symbolic model/mathematical model

13. General methods of solving OR models
• Analytic model
• Iterative model
• Monte carlo simulation model

14. TECHNIQUES/TOOLS/OF OR
• allocation models
• sequencing
• waiting line models or queuing theory
• inventory models
• game theory
• decesion theory
• network analysis
• simulation
• replacement models

15. PHASES /PROCESS OR METHODOLOGY OF OR
• FORMULATING THE PROBLEM
• CONSTRUCTING THE MODEL
• DERIVING THE SOLUTION
• TESTING THE VALIDITY
• CONTROLLING THE SOLUTION
• IMPLEMENTING THE RESULTS

16. LIMITATIONS OF OR
• OR tries to find out optimum solution,taking all the factors
into account.when there are large number of factors
invovled a study of all of them become diffficult or
imposssible
• The solution in a problem can be obtained by ‘OR’
techniques, only if the problem can be quantified.
• It is not easy to quantify all elements particularly when
they are intangible.
• ‘OR’ is a specialist job. It requires the effort of
mathematicians and managers put together

17. • When the basic data are subject to frequent changes,
incorporating them in the ‘OR’ models is a costly affair.
• Greatest difficulty is created by time factor
• A solution and the right time will be more useful that a
perfect solution arrived later. Therefore a problem of
choosing between timely solution