4. Rules of thumb or heuristics are often used to aid decision-making. For example, a financial institution may choose to lend three times a person's salary in considering a mortgage application. These rules provide broad guidelines for mangers in decision-making. They are often based on expert judgement and experience and supplemented with other information.
5. As a preliminary step, an NHS body could, therefore, draw on expert opinion and information from comparable schemes to determine what allowance to make for risk. Evidence bases will continue to be established in the public sector. Probability analysis will complement these.