Transcript Methodology for Architectural Level Reliability Risk Analysis Lalitha Krothapalli CSC 532

Methodology for Architectural
Level Reliability Risk Analysis
Lalitha Krothapalli
CSC 532
Risk
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Risk is a combination of two factors.
Probability of malfunctioning( failure)
Consequence of malfunctioning
(severity)
Uses of Risk Assessment
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Finding out the complex modules.
Finding out the potentially troublesome
modules.
Calculates the effort for testing.
Types of Risks
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Availability Risk.
Acceptance Risk.
Performance Risk.
Cost Risk.
Schedule Risk
Reliability Risk.
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Architectural level
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System is divided in to two parts
Components: Like objects, classes or
procedures.
Connectors: Procedural calls , Clientserver protocols
Advantage of Architectural Risk
Analysis
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Early detection and correction of errors
Cost will be less.
Design and coding are also depend on
the complexity of the architecture.
Advantages of simulating the
Architecture Model
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Obtain dynamic behavior of
components and connectors using
dynamic metrics.
Study the consequences of failure and
severity of that failure.
Background
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The proposed methodology is based on
the previous work of
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Dynamic Metrics
Reliability Modeling and Analysis of
Software Architecture
Dynamic Metrics
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Used to find out the complexity of each
component
Executive components have lot of state
changes
Measures the impact on the maintainability,
reusability and error proneness
Connector complexity can be calculated by
using dynamic coupling metrics
Component Dependency
Graphs
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Used to find out the reliability analysis
at the architectural level.
Represents components, connectors
and component, connector reliabilities
Can be used to calculate the execution
time of the components and the
interaction between the components
Risk Assessment Methodology
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Usage of architectural description language
for modeling system architecture.
Calculate complexity analysis using
simulation of the architecture.
Obtain severity analysis using FEMA and
simulation runs.
Developing heuristic risk factors for
components and connectors.
Preparing CDGs for calculating risk
assessment.
Architectural Modeling
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Interaction between the components
Behavior of individual components
Real time object oriented model can be
used to simulate the architecture
Complexity Analysis
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Component Complexity
Connector complexity
Severity analysis
Identifying failure modes.
- failures modes of Individual components.
- failure modes of individual connectors.
 Conducting Effect Analysis.
 Ranking severity.
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Catastrophic
Critical
Marginal
Minor.
Develop Reliability Risk Factors
for Architecture Elements
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Heuristic Factor for a component
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Heuristic factor for a connector.
Developing Component
Dependency Graphs
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Calculate the execution time of each
scenario.
Calculate the execution time of each
component
Calculate the transition probability
from one component to other for each
and every scenario.
Predict the complexity factor and
severity of the index of the each
component.
Reliability Risk Analysis Algorithm
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The risk factor of a system can be
obtained from aggregating the risk
factors of all components and
connectors
Breadth of a graph - All risk factors
Depth of a graph
execution
- Sequential
Conclusion
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Applicable to architecture level so the
errors can identified and detected at
the early stages of life cycle.
Based on dynamic metrics .
Automatable.
References
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1. Volume: 28, Issue: 6, Year: Jun 2002
A methodology for architecture-level reliability risk
analysis
Yacoub, S.M.; Ammar, H.H.
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Page(s): 529-547
2. 1 Architectural-level risk analysis using UML
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Software Engineering, IEEE Transactions on , Volume: 29
, Issue: 10 , Oct. 2003
Pages:946 – 960
3. 7 Risk analysis-a subjective process
Goseva-Popstojanova, K.; Hassan, A.; Guedem, A.; Abdelmoez,
W.; Nassar, D.E.M.; Ammar, H.; Mili, A.;
Redmill, F.;
Engineering Management Journal , Volume: 12 , Issue: 2 , April
2002
Pages:91 – 96