This paper points out that the decision\|making for flood control and dispatching systems is a multi\|objective and semi\|structural decision\|making including qualitative objectives and quantitative objectives.

：The decision-making for multi-objective system is a semi-structural decision-making that includes qualitative objectives and quantitative objectives.

This paper systematically analyzes main factors affecting the decision of bracing system for deep foundation pits; establishes an index system of evaluation scheme and a multiobjective fuzzy optimum model of bracing schemes through fuzzy mathematical theory; and puts forward rational methods of the definiteness of objective weight and quantitating qualitative objects.