The roots of Operations Research (OR) are as old as science itself. The science of OR came into existence in connection with the war operations, to decide the strategy by which the enemy could be harmed to the maximum possible extent with the help of the available warfare. It was in 1885 that Frederick W. Taylor first emphasized the application of scientific analysis to methods of production. He conducted an experiment with a shovel trying to find out the weight load of ore moved by the shovel that would result to a maximum ore moved with minimum fatigue. The experiment yielded optimum weight load which provided maximum ore movement. Productivity rose substantially after this change. Other early researchers that improved scientific management are Henry Gantt with the job-scheduling improvement, A. K Erlang with his work on telephone traffic decongestion in 1917, and so many others. The field of OR continued to grow with industrial revolutions. Today, the impact of OR can be felt in so many areas. Of late, OR activities have spread to diverse fields such as hospitals, libraries, city planning, transportation systems, crime investigation, energy conservation, environmental pollution, etc.
1.2 DEFINITION
OF OPERATIONS RESEARCH:
Many
definitions of operations research have been suggested from time to time and it
is difficult to define due to its wide scope of application. Firstly, an
operation is a set of actions required for the achievement of a desired
outcome. The inter-related acts can be performed by man, machine, and
man-machine units. One of the most comprehensive definitions of OR given by J.
O .R Society, UK states that O. R is the application of modern methods of
mathematical science to complex problems involving management of large systems
of men, machines, materials and money in industry, business, government and
defence. The distinctive approach is to develop a scientific model of the
system incorporating measurement of factors such as chance and risk to predict
and compare the outcomes of alternative decisions, strategies or controls.
1.
It
has a system orientation or holistic approach - This
means that any activity by any part of an organization has some effect on the
activity of every other part. Therefore to evaluate any decision, one has to
identify all possible interactions and determine their impact on the
organization as a whole. It is necessary that the problem be analyzed with
painstaking care and all parts of the organization affected be thoroughly
examined. When all factors affecting the system or organization are known, a
mathematical model can be prepared. A solution to the model will now optimize
the profits to the system as a whole.
2.
The
use of interdisciplinary teams – The OR study is
performed by a team of scientists whose individual members have been drawn from
various scientific and engineering disciplines. for example, one may find a mathematician, statistician,
physicist, psychologist, economist and an engineer working on a particular OR
problem. This will make the solution more unique and have a greater probability
of success.
3.
Use
of a computer – OR often requires a computer to solve
complex mathematical model or to manipulate a large amount of data and for
other computations
4.
Use
of a scientific method – OR uses scientific method to solve
problems. The representation of the system and its operations is constructed
with a model for the study or research.
5.
Improvement
in quality of decisions taken – OR gives bad answers to
problems, to which, otherwise, worse answers are given. This implies that the application of OR can only improve the
quality of the solution gotten from the model but it cannot give a perfect
solution.
6.
Quantitative
solutions – The use OR in management provides a
quantitative basis for decision making.
SCIENTIFIC METHODS IN OPERATIONS
RESEARCH
There
are three main phases of the scientific methods employed in operations
research;
i.The judgment phase
ii.The
research phase
iii.The
action phase
Judgment phase – This
consists of;
a) Determination
of the operation: Any operation, which is a combination of actions that
utilizes resources (e.g., man and machines) to complete an aim will always be
associated with problems before a successful completion.
b) Determination
of objectives and values of the operation: In this phase, considerable effort
is put in place to find the type of situation involved (engineering,
manufacturing, tactical, etc). The amount of risks involved, other areas
affected by solution, objectives and values must be carefully determined so as
to have a clear approach to the solution of the problem.
c) Determination
of effectiveness measure: There should be an effective way of knowing how
successful the model is in representing the problem and providing a solution.
These measures form the link between the objectives and the analysis required
for corrective action. It tests the correctness of the solution and determines
if there is a need for improving the method. Measures of effectiveness are
usually expressed in terms of ratio or rate (e.g. number of cars per accident
in traffic studies).
d) Formulation
of the problem relative to the objectives: the operations analyst must
determine the type of problem (prediction type e.g. forecasting problems that
will be associated with future development, remedial type e.g. plane crash
where the origin is in actual or threatened accidents, optimization type, etc),
its origin and causes. Before selecting a problem for investigation, careful
thought must be given to find whether the problem actually exists as hasty
selection of problems often leads to wastage of time.
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