Page 423 - Safety Risk Management for Medical Devices

402 Index

Safety (Continued) fault, 129
safety-requirements, 176 item, 128 129
security influence on, 123 maintenance and risk management, 146 147
violations, 6 reliability vs. software safety, 147 149
Sample tips for developing safety-critical software,
risk controls, 168 169 148 149
size, 176 risk analysis, 130 132
SC fault. See State of component fault (SC fault) analysis process, 140f
Scalpel, 121 risk control, 138 139
Scope, 94 risk in system, 129
setting safety, 129
in DFMEA, 94 95 classification, 137 141
in PFMEA, 104 sources, 133
in UMFMEA, 113 system, 128 129, 137 138
Second layer nodes, 76 testing, 129
Secondary faults, 70 unit, 128 129
judicious in modeling, 75 Software Failure Modes, 133
Secondary function identification Software Failure Modes and Effects Analysis
in DFMEA, 95 (SFMEA), 80 81, 131 137. See also Use-
in PFMEA, 104 Misuse Failure Modes and Effects Analysis
in UMFMEA, 113 (UMFMEA)
Security criticality table, 136t
influence on safety, 123 detectability ratings, 136t
risk analysis, 123 occurrence ratings definitions, 135t
security-relating hazards, 123 severity ratings definitions, 134t
Semiquantitative method, 157 159, 173 174 template, 245 249
risk evaluation for, 173 174 workflow, 132 137
Sensitivity evaluation, 69 70 Software of Unknown Pedigree (SOUP), 146
Serious adverse device effect, 204 Software of Unknown Provenance (SOUP), 130,
Serious adverse event (SAE), 204 146
Serious Injury, 138 Software risk management, 129
Sev. See Severity (S) BXM method for software risk analysis,
Severity (S), 84 86, 98, 106, 114, 134, 161, 227 141 142
example, 158t legacy software, 141 142
ranking, 98, 134 new software, 142
SFMEA. See Software Failure Modes and Effects legacy software, 144 146
Analysis (SFMEA) risk controls, 142 144
Single fault condition, 211 RMF additions, 142
Single Harm-severity method, 59 SFMEA, 132 137
Single-fault-safe criticality table, 136t
design, 163 164 detectability ratings, 136t
interpretation, 164 occurrence ratings definitions, 135t
Slip, 32 34 severity ratings definitions, 134t
Software, 127 workflow, 132 137
contribution to Hazards and Harms, 128 software reliability vs. software
defect, 129 safety, 147 149
events chain, 129, 130f tips for developing safety-critical software,
failure, 129, 132 148 149