The Rational Manager (a methodology for problem solving/decision making)
It is a classic. If you like a structured, analytical method for solving problems and making decisions - get it.
Fatally Flawed
For a sound decisionmaking system, read The Choosing By Advantages Decisionmaking System by Jim Suhr. Forget the unsound practices of weighting, rating, and calculating.
Now in a new edition
Used this in college in the '60s. Great for a structured approach to decision making and problem solving. Makes you think about problems differently often providing additional insight.