Creativity is the ability to identify self-imposed constraints, remove them, and explore the consequences of their removal.

The most valuable and least replacable resource is time.

Managers are not confronted with problems that are independent of each other, but with dynamic situations that consist of complex systems of changing problems that interact with each other. I call such situations messes. Problems are extracted from messes by analysis. Managers do not solve problems, they manage messes.

Every problem interacts with other problems and is therefore part of a set of interrelated problems, a system of problems. I choose to call such a system a mess.

Managers who don't know how to measure what they want settle for wanting what they can measure.

In systems thinking, increases in understanding are believed to be obtainable by expanding the systems to be understood, not by reducing them to their elements. Understanding proceeds from the whole to its parts, not from the parts to the whole as knowledge does.

Common sense … has the very curious property of being more correct retrospectively than prospectively. It seems to me that one of the principal criteria to be applied to successful science is that its results are almost always obvious retrospectively; unfortunately, they seldom are prospectively. Common sense provides a kind of ultimate validation after science has completed its work; it seldom anticipates what science is going to discover.