Tornado charts are useful for deterministic sensitivity analysis – comparing the relative importance of variables. For each variable/uncertainty considered, one needs estimates for what the low, base, and high outcomes would be. The sensitive variable is modeled as having an uncertain value while all other variables are held at baseline values This allows testing the sensitivity/risk associated with one uncertainty/variable. For example, if a decision maker needs to visually compare 15 variables, and wishes to identify the five that are most impactful, a tornado chart can be very useful. In this example, the top five bars would represent the variables that contribute the most to the variability of the outcome, and therefore may help the decision maker focus their attention and/or guide scenario generation.