PMBOK(2004 3rd 英) P257关于风险定量分析模型技术中有一种技术叫敏感性分析(Sensitivity Analysis), 用于比较各种风险在其他风险处于基准水平的情况下对项目整体产生的影响大小，从而来找出影响最大的风险。龙卷风图(tornado diagram)是一种常用的技术，书中没有详细说明龙卷风图,也没有图例。

http://international.fhwa.dot.gov/riskassess/risk_hcm06_04.htm 给出了龙卷风的解释，并且给出了图例：

Sensitivity analysis is a primary modeling tool that can be used to assist in valuing individual risks, which is extremely valuable in risk management and risk allocation support. A "tornado diagram" is a useful graphical tool for depicting risk sensitivity or influence on the overall variability of the risk model. Tornado diagrams graphically show the correlation between variations in model inputs and the distribution of the outcomes; in other words, they highlight the greatest contributors to the overall risk.

The tornado diagram has a central vertical axis from which bars extend left and right, their length corresponding to the influence of the factors they represent on risk. The bars are ordered so that they decrease in influence as they go down.





上面的图形是不是很像龙卷风