文档介绍：ցցցցցցցցցցց
An Introduction to Model Building
An Introduction to Modeling
Operations research (often referred to as management science) is simply a scientific
approach to decision making that seeks to best design and operate a system, usually un-
der conditions requiring the allocation of scarce resources.
By a system, we mean anization of ponents that work together
to plish the goal of the system. For example, Ford pany is a system whose
goal consists of maximizing the profit that can be earned by producing quality vehicles.
The term operations research was coined during World War II when British military
leaders asked scientists and engineers to analyze several military problems such as the de-
ployment of radar and the management of convoy, bombing, antisubmarine, and mining
operations.
The scientific approach to decision making usually involves the use of one or more
mathematical models. A mathematical model is a mathematical representation of an ac-
tual situation that may be used to make better decisions or simply to understand the ac-
tual situation better. The following example should clarify many of the key terms used to
describe mathematical models.
EXAMPLE 1 Maximizing Wozac Yield
Eli Daisy produces Wozac in huge batches by heating a chemical mixture in a pressur-
ized container. Each time a batch is processed, a different amount of Wozac is produced.
The amount produced is the process yield (measured in pounds). Daisy is interested in
understanding the factors that influence the yield of the Wozac production process. De-
scribe a model-building process for this situation.
Solution Daisy is first interested in determining the factors that influence the yield of the process.
This would be referred to as a descriptive model, because it describes the behavior of the
actual yield as a function of various factors. Daisy might determine (using regression
methods discussed in Chapter 24) that the following