Scientists possess healthy skepticism. They realize that you've got to know the answer before you measure it. - Robert E. Machol

The conclusions of most good operations research studies are obvious.

The lack of formal definition does not prevent us from noting the characteristics which are frequently present in large scale systems. Each such system has a certain integrity. It may or may not be rigidly controlled from some central point, but in every case, all the parts of the system have some common purpose; in some sense, they all contribute to the production of a single set of optimum outputs from the given set of inputs, with respect to some appropriate measure of effectiveness.

[Systems should be classified] on the basis of the types of inputs with which they must cope.