Table 3.

Failure modes and accompanying RPN scores for identified failure modes for a situation where the patient is on treatment, the physician changes a plan, the number of fractions is kept constant, and no resimulation is required

Failure mode	Impact	RPN with record and verify (occurrence, detectability, severity)	RPN with no record and verify (occurrence, detectability, severity)	Percent increase (%)
Did not schedule new plan/old fields not hidden	Patient gets treated with old plan/field	84 (4, 3, 7)	210 (6, 5, 7)	125
New plan gets planned/scheduled for wrong number of fractions	Wrong total dose	72 (4, 3, 6)	96 (4, 4, 6)	33
Average ± SD		78 ± 8	153 ± 81	96

Abbreviation: RPN = Risk Priority Number.

Data are presented for situations with and without a Record and Verify system being available. The rows are ordered in order of highest to lowest RPN score for the situation with no record and verify system availability.