Post on 01-Jan-2016
description
Attributes
AvailabilityReliabilitySafetyConfidentialityIntegrityMaintainability
Dependability Means
Fault PreventionFault ToleranceFault RemovalFault Forecasting
ThreatsFaultsErrorsFailures
ability to deliver service that can justifiably be trusted
Risk definition and expression
Negligible Marginal Critical Catastrophic
Frequent
Probable
Occasional
Remote
Improbable
Pro
bab
ility
of
occ
urr
ence
Mishap severity
High
MediumLow
Serious
Probabilities of occurrence and mishap severity
Appliocation domains (transportation, energy production, telecommunications,
banking, etc.)
IEC 61508 (1998) – Combination of the probability of a damage and of its severity
MIL-STD-882D (Février 2000) – An expression of the impact and possibility of a mishap in terms of potential mishap severity and probability of occurrence
Risk assessment Practices vary according to countries
France: ‘globally at least as relevant’ (GAMAB) UK: ‘As low as reasonably possible’ (ALARP) Germany: ‘Minimum endogenous mortality’ (MEM)
Risk management Current situation: Risk level strength of
verification and validation activities Software considerations in airborne systems
and equipment certification, DO-178-B Common Criteria for Information Technology
Security Evaluation, ISO/IEC Standard 15408
Means for dependability
Fault PreventionFault ToleranceFault RemovalFault Forecasting
Verificationand Validation
Addressed faults (e.g., accidental, malicious)Coverage
Demonstration, analytical and experimentalDiversity