树形决策法是各备选方案的一连串因素按它们之间的相互关系用树形图表示出来,并以定量方法计算和比较各备选方案的结果,以取得决策时最优解决的方法。其基本步骤如下:第一步,绘制决策树图形。决策树是以方案和园圈为结点,并由直线连接而形成的一种象树枝形状的结构。方框结点叫决策点。由决策点引出若干条树枝(直线),每条树枝代表一个方案,故称这些树枝为方案枝。在各方案枝的末端画上一个园圈,就是园圈结点或叫机会点。由机会点引出若干条树枝(直线), The tree-based decision-making method is a series of factors of each alternative plan, which is represented by a tree diagram according to the mutual relationship between them and the result of each alternative plan is calculated and compared quantitatively to obtain the optimal solution method. The basic steps are as follows: The first step, draw the decision tree graphics. Decision tree is based on the program and the circle as a node, and formed by a straight line like a branch-shaped structure. Box node called the decision point. Derived from the decision-making point of a number of branches (straight line), each branch represents a program, so that these branches for the program branch. Draw a circle at the end of each branch, which is called circle node or opportunity point. From the point of opportunity leads to a number of branches (straight line),