Failure mode and effect analysis (FMEA) is a systematic method for identifying potential problems and their impact on a process.

Regarding the failure that has been identified, how severe could the resulting harm be if it is not stopped? Would the harm be:

1. Minor – the patient does not need any additional care
2. Moderate – the patient needs some additional care
3. Major – permanent physical or psychological injury to the patient, the patient needs surgical intervention, or additional care is needed for multiple patients
4. Catastrophic – where death or major injury would be expected to occur.

The respective rating, on a scale of 1 to 4, gives the severity, or S.

Next, how likely is it that each failure would occur?

1. Remote – sometime in five to 30 years
2. Uncommon – sometime in two to five years
3. Occasional – several times in one to two years
4. Frequent – several times in one year.

This rating, on a scale of 1 to 4, gives the likelihood, or L.

Then, how likely is it that each failure would be detected in time to prevent any harm?

1. Very likely – would always be detected
2. Likely – would be detected on most occasions
3. Unlikely – would be detected on only a few occasions
4. Not at all likely – would never be detected.

This rating, on a scale of 1 to 4, gives the detectability, or D.