Summing Independent Scenarios Understates Your Tail
A quantification program with a dozen scenarios usually produces its annual figure by adding them together. Each scenario was modeled carefully, the arithmetic is simple, and the result is close to right for one of the two numbers the model produces. Summing scenarios treats them as independent, and cyber scenarios share dependencies. The consequence is specific rather than general, and it is worth being precise about because it determines which decisions the resulting figure can support.