Operations research, rather simply defined, is the research of operations. An operation may be called a set of acts required for the achievement of a desired outcome. Such complex, inter-related acts can be performed by four types of systems: Man, Machine, Man-machine unit and any organization of men, machines, and man-machine units. Operations research is concerned with the opearations of the last type of system. According to Morse & Kimball, Operation Research is a scientific method of providing executive departments with a quantitative basis for decisions regarding the operation under their control...

Linear programming is a technique for specifying how to use limited resources or capabilities of a business to obtain a particular objective, such as least cost, highest margin, or least time, when these resources have alternate uses. A linear programming problem has two basic parts: (i)the objective function, whichdescribes the primary purpose of the formulation-to maximize cost, and (ii)the constraint set, which is a system of equalities and/or inequalities describing the restrictions (conditions or constraints) under which optimization is to be accomplished. (For example, these restrictions may be on machine time, man-hours, materials, contract specification, etc.)...

All linear programming problems can be solved by simplex method, but certain special problems lend themselves to easy solution by other methods. One such case is that of Transportation problems. Transportation problems are encountered in physical distribution of goods. Source of supply, availibility of material for distribution, the requirement of demand at particular place or destination or at numder of destinations are some of the parameters involved in the problem. The objective is to minimize the cost associated with such transportation from place of supply to places of demand within given constraints of availability and level of demand. These distribution problems are amenable to solution by a special type of Linear Programming model know as 'Transportation Model'. It can also be applied to the maximization of some utility value such as financial resources...

Network analysis is a system which plans projects both large and small by analyzing the project activites. When all these activites are arranged in logical sequence, a network diagram is one which presents visually the relationship between all the activities involved. Time, cost and other resources are allocated to different activites.. Network analysis helps designing, planning co-ordinating, controlling and decision making in order to accomplish the project economically in the minimum available time with the limited resources. Network techniques are developed from milestone chart and bal chart. Programme Evaluation and review Technique (PERT) and Critical Path Method (CPM) represent the two-well known network analysis techniques used to aid the manager in planning and controlling large scale construction...

Data refers to a collection of facts usually collected as the result of experience, observation or experiment, or processes within a computer system, or a set of premises. This may consist of numbers, words, or images, particularly as measurements or observations of set of variables. Data is often viewed as a lowest level of abstraction from which information and knowledge are derived...

Correlation is a statistical tool which studies the relationship between two variables. Two variables are said to be correlated if the change in one variable results in corresponding change in the other variable is called correlation coefficient. For example, there exists some relationship between age of husband and age of wife, price of a commodity and amount demanded, etc. A very simple definition of correlation is that given by A.M. Tuttle. He defines correlation as: "An analysis of the covariation of two or more variables is usually called correlation."...

The queuing theory or waiting line theory owes its development to A.K.Erlang. He, in 1903, took up the probelm on congestion of telephone traffic. The difficulty was that during busy periods, telephone operators were unable to handle the calls the moment they were made, resulting in delayed calls. A.K.Erlang directed his first efforts at finding the delay for one operator and later on the results were extended to find the delay for several operators. The field of telephone traffic was further developed by Molins (1927) and Thornton D-Fry (1928). However, it was only after World War II that this early work was extended to other general probelms involving queues or waiting lines...

Simulation is a numerical technique for conducting experiments on a digital computer, which involves logical and mathematical relationships that interact to describe the behaviour and structure of a complex real-world system over a extended periods of time. Simulation has often been descirbed as the process of creating the essence of reality without ever actually attaining that reality itself. Simulation is the next best thing to observing a real system on operation. It allows us to collect pertinent information about the behaviour of the system by executing a computerized model. The collected data are then used to design the system. Rather, it is a teachnique for estimating the measures of performance of the modeled system. Simulation is the imitation of some real thing, state of affairs, or process. The act of simulating something generally entails representing certain key characteristics or behaviors of a selected physical or abstract system...