Unlike most introductions to systems theory I have read, this one goes for the proper concepts, differential equations, but with very little use of mathematics. Like all Weinberg books, it's rather chatty, so it's a matter of taste whether you like the style, but what was extremely useful for me was the way he used game theory for designing external regulation. In other words, control is conflict, something that is highly useful to understand when you work with concepts like TQM or ISO 9000. Weinberg also states that this book is intended as the second book in a trilogy of systems books. Does anybody know whether he completed the final book in the series?