smu fall assignment 2014 Mb00 48 operaton research

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Question1: Discuss the methodology of Operations Research. Explain in brief the phases
of Operations Research.
Answer: Definitions of operations research Churchman, Aackoff, and Aruoff defined
operations research as “the application of scientific methods, techniques and tools to the
operation of a system with optimum solutions to the problems” where 'optimum' refers to the
best possible alternative. The objective of OR is to provide a scientific basis to the decision-
makers for solving problems involving interaction with various components of the organization.
This can be achieved by employing a team of scientists from different disciplines to work
together for finding the best possible solution in the interest of the organization as a whole. The
solution thus obtained is known as an optimal decision.
You can also define operations research as “The use of scientific methods to provide criteria for
decisions regarding man, machine, and systems involving repetitive operations.”
Operations Research Methodology
The basic dominant characteristic feature of operations research is that it employs mathematical
representations or models to analyze problems. This distinct approach represents an adaptation of
the scientific methodology used by the physical sciences. The scientific method translates a
given problem into a mathematical representation which is solved and retransformed into the
original context. Figure depicts the OR approach to problem solving.
Steps in the OR methodology
As shown in figure, OR methodology consists of five steps. They are - defining the problem,
constructing the model, solving the model, validating the model, and implementing the result.
Let us now study the steps in detail.
1 Definition The first and the most important step in the OR approach of problem solving is to
define the problem. One needs to ensure that the problem is identified properly because this
problem statement will indicate the following three major aspects:
 Description of the goal or the objective of the study
 Identification of the decision alternative to the system
 Recognition of the limitations, restrictions, and requirements of the system
2 Constructions Based on the problem definition, you need to identify and select the most
appropriate model to represent the system. While selecting a model, you need to ensure that the
model specifies quantitative expressions for the objective and the constraints of the problem in
terms of its decision variables. A model gives a perspective picture of the whole problem and
helps in tackling it in a wellorganised manner. Therefore, if the resulting model fits into one of
the common mathematical models, you can obtain a convenient solution by using mathematical
techniques. If the mathematical relationships of the model are too complex to allow analytic

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solutions, a simulation model may be more appropriate. Hence, appropriate models can be
constructed.
3 Solution After deciding on an appropriate model, you need to develop a solution for the model
and interpret the solution in the context of the given problem. A solution to a model implies
determination of a specific set of decision variables that would yield an optimum solution. An
optimum solution is one which maximizes or minimizes the performance of any measure in a
model subject to the conditions and constraints imposed on the model.
4 Validation A model is a good representation of a system. However, the optimal solution must
work towards improving the system’s performance. You can test the
Validity of a model by comparing its performance with some past data available from the actual
system. If under similar conditions of inputs, your model can reproduce the past performance of
the system, then you can be sure that your model is valid. However, you will still have no
assurance that future performance will continue to duplicate the past behavior. Secondly, since
the model is based on careful examination of past data, the comparison should always reveal
favorable results. In some instances, this problem may be overcome by using data from trial runs
of the system. One must note that such validation methods are not appropriate for non-existent
systems because data will not be available for comparison.
5 Implementation You need to apply the optimal solution obtained from the model to the
system and note the improvement in the performance of the system. You need to validate this
performance check under changing conditions. To do so, you need to translate these results into
detailed operating instructions issued in an understandable form to the individuals who will
administer and operate the recommended system. The interaction between the operations
research team and the operating personnel reaches its peak in this phase.
Phases of Operations Research
The scientific method in OR study generally involves three phases.
Phases of Operations Research
Let us now study the phases in detail.
Judgment phase This phase includes the following activities:
operations
Research phase This phase utilizes the following methodologies:

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additional data
using pre-established measure of effectiveness
Action phase This phase involves making recommendations for the decision process. There
commendations can be made by those who identify and present the
Problem or by anyone who influences the operation in which the problem Has occurred
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Last date of submission 30/6/2014