Despite the definitude optimizing method is general, more and more designers realize that the material properties 、 member measurements and the outside actins are stochastic geometry quantities or physical quantities . therefore, the optimizing design of project should be changed from determine to undetermined 尽管确定性的优化方法目前应用普遍,但是目前已经开始认识到材料性能,构件尺寸以及结构外来作用都是随机的几何量或物理量,而不是确定的单值量。