Determining the probability and the magnitude of the risk can be difficult and can seem
to be arbitrarily chosen. One means of determining the risk probability is for each team
member to estimate each of these values individually. Then, the input of individual team
members is collected in a round robin fashion and reported to the group. Sometimes the
collection and reporting is done anonymously. Team members debate the logic behind
the submitted estimates. The individuals then re-estimate and iterate on the estimate until
assessment of risk probability and impact begins to converge. This means of converging
on the probability and estimate is called the Delphi Technique (Gupta and Clarke, 1996).
The Delphi Technique is a group consensus method that is often used when the factors
under consideration are subjective.