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Stochastic Programming - Index of

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1<br />

Basic Concepts<br />

1.1 Motivation<br />

By reading this introduction, you are certainly already familiar with<br />

deterministic optimization. Most likely, you also have some insights into what<br />

new challenges face you when randomness is (re)introduced into a model.<br />

The interest for studying stochastic programming can come from different<br />

sources. Your interests may concern the algorithmic or mathematical, as well<br />

as modeling and applied aspects <strong>of</strong> optimization. We hope to provide you with<br />

some insights into the basics <strong>of</strong> all these areas. In these very first pages we<br />

will demonstrate why it is important, <strong>of</strong>ten crucial, that you turn to stochastic<br />

programming when working with decisions affected by uncertainty. And, in in<br />

our view, all decision problems are <strong>of</strong> this type.<br />

Technically, stochastic programs are much more complicated than the<br />

corresponding deterministic programs. Hence, at least from a practical point<br />

<strong>of</strong> view, there must be very good reasons to turn to the stochastic models. We<br />

start this book with a small example illustrating that these reasons exist. In<br />

fact, we shall demonstrate that alternative deterministic approaches do not<br />

even look for the best solutions. Deterministic models may certainly produce<br />

good solutions for certain data set in certain models, but there is generally<br />

no way you can conclude that they are good, without comparing them to<br />

solutions <strong>of</strong> stochastic programs. In many cases, solutions to deterministic<br />

programs are very misleading.<br />

1.1.1 A numerical example<br />

You own two lots <strong>of</strong> land. Each <strong>of</strong> them can be developed with necessary<br />

infrastructure and a plant can be built. In fact, there are nine possible<br />

decisions. Eight <strong>of</strong> them are given in Figure 1, the ninth is to do nothing.<br />

The cost structure is given in the following table. For each lot <strong>of</strong> land we<br />

give the cost <strong>of</strong> developing the land and building the plant. The extra column<br />

will be explained shortly.

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