In ISO 14197 and other places, there is a table to help people decide about acceptable risk. A reproduction of this table follows. Here’s why this table is silly.
This table says a frequent catastrophic error is unacceptable – duh! For example, half of the surgeries in a hospital are performed at the wrong site or patient. One doesn’t need a risk management standard to tell us this is unacceptable.
Perhaps the most important function of risk management is to prevent catastrophic errors. For any reasonable process in healthcare, the above table really looks like the one below.
The use of question marks suggests that it is difficult to really know when the risk is acceptable, but there always is a point where the remaining risk has to be acceptable because risk is never zero and funds are limited. But most of the effort should go into reducing risk of catastrophic errors.
To deal with all errors, the following table is suggested.