Failure Mode and Effects Analysis (FMEA): Risk Acceptance Matrix

This document defines under which circumstances risk are acceptable. It defines probabilities and severities and each probability-severity combination is either acceptable or not, as shown in the risk acceptance matrix at the bottom.

Risk Policy

Radiotherapy AI’s products should not cause more harm than undergoing the process manually without AI assistance.

Severity

Severity	Definition and Examples
S1: Negligible	Delay of treatment or clinically non-relevant protocol deviation
S2: Minor	Minor radiotherapy protocol deviation, non-patient identifying data leak
S3: Major	Major radiotherapy protocol deviation, or patient identifying data leak
S4: Critical	Reportable radiotherapy mistreatment and/or incident
S5: Death

Probability

Probability	Upper Limit	Lower Limit	Estimated Maximum Event Count
P6: Almost certain	1	10^-2	10000000
P5: Likely	10^-2	10^-4	100000
P4: Possible	10^-4	10^-6	1000
P3: Unlikely	10^-6	10^-8	10
P2: Rare	10^-8	10^-10	0
P1: Almost impossible	10^-10	0	0

Risk Acceptance Matrix

Probability	S1: Negligible	S2: Minor	S3: Major	S4: Critical	S5: Death	Estimated Maximum Event Count
P6: Almost certain	unacceptable	unacceptable	unacceptable	unacceptable	unacceptable	10000000
P5: Likely	acceptable	unacceptable	unacceptable	unacceptable	unacceptable	100000
P4: Possible	acceptable	acceptable	unacceptable	unacceptable	unacceptable	1000
P3: Unlikely	acceptable	acceptable	acceptable	unacceptable	unacceptable	10
P2: Rare	acceptable	acceptable	acceptable	acceptable	unacceptable	0
P1: Almost impossible	acceptable	acceptable	acceptable	acceptable	acceptable	0