By dividing the decision-making system into several subsystems (that is, decomposing the decision-making problem into local small problems), and listing their characteristics one by one. These characteristics are divided into conceptual constraints, changing rules and so on. And study whether these characteristics can be changed, and the influence on decision-making after the change, and study the methods to solve decision-making problems. The advantage of this method is that it can ensure a comprehensive study of all aspects of the problem.