Calculated risk probability is different than assigned probability.

[Col]

I have assigned a risk to a resource(s) as a relative time increase and then also as a relative cost increase – both at 15% chance with 10% outcome. But the issue I seem to have when I do this is that the probability of it occurring goes above 15%. Do I potentially need to add the time delay to the task and cost increase to the resources(s) Or am I going about this all the wrong way.

[Intaver Support]

Calculated probability can vary from the input. But normally not by much. The reason is similar to throwing a dice. At each iteration, the risk has a 15% of occurring, so after 1 iteration, the probability will be 0 or 100%, after 2 throws 0,50, or 100%. After 100 iterations, it could occur 15x (ie 15%) but could be less or more. The more iterations that are run, the closer the probability will be to 15%.