cse 322: software reliability engineering topics covered: dependability concepts dependability...
Post on 20-Dec-2015
227 views
TRANSCRIPT
CSE 322: Software Reliability Engineering
Topics covered:Dependability concepts Dependability models
Dependability tree
Dependability
Attributes
Means
Impairments
AvailabilityReliabilitySafetyConfidentialityIntegrityMaintainability
Fault preventionFault removalFault toleranceFailure forecasting
FaultsErrorsFailures
Classification of faults
Physical faults:
Design faults:
Interaction faults:
Design and interaction faults are human-made. Can be further classified as:
Classification of faults (contd..)
Intentional, non malicious design faults:
Intentional, malicious interaction faults:
Classification of faults (contd..)
Intentional, malicious design faults:
Intentional, malicious interaction faults:
Dependability tree
Dependability
Attributes
Means
Impairments
AvailabilityReliabilitySafetyConfidentialityIntegrityMaintainability
Fault preventionFault removalFault toleranceFailure forecasting
FaultsErrorsFailures
Attributes (contd..)
Integrity:
Maintainability:
Security:
Performability:
Relative significance of dependability attributes:
Dependability tree
Dependability
Attributes
Means
Impairments
AvailabilityReliabilitySafetyConfidentialityIntegrityMaintainability
Fault preventionFault removalFault toleranceFailure forecasting
FaultsErrorsFailures
Dependability models
Measures of interest: Reliability Availability
Dependability evaluation:
Dependability models:
Combinatorial models: Example
Consider a multiprocessor system consisting of two processors and two memory units. For the system to be functioning, at least one processor and one memory unit should be up, else the system fails. Let the reliability of the processor be denoted Rp, and the reliability of the memory unit be denoted Rm. Construct a reliability block diagram and a fault tree model to evaluate the reliability of the multiprocessor system. Derive an expression for system reliability in both these cases.