Post on 23-Dec-2015
Methodology for Architectural Level Reliability Risk Analysis
Lalitha KrothapalliCSC 532
Risk
Risk is a combination of two factors.
1. Probability of malfunctioning( failure)
2. Consequence of malfunctioning (severity)
Uses of Risk Assessment
Finding out the complex modules. Finding out the potentially
troublesome modules. Calculates the effort for testing.
Types of Risks
Availability Risk. Acceptance Risk. Performance Risk. Cost Risk. Schedule Risk Reliability Risk.
Architectural level System is divided in to two parts
Components: Like objects, classes or procedures.
Connectors: Procedural calls , Client- server protocols
Advantage of Architectural Risk Analysis
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
Obtain dynamic behavior of components and connectors using dynamic metrics.
Study the consequences of failure and severity of that failure.
Background
The proposed methodology is based on the previous work of Dynamic Metrics Reliability Modeling and Analysis of
Software Architecture
Dynamic Metrics 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
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 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
Interaction between the components
Behavior of individual components Real time object oriented model
can be used to simulate the architecture
Complexity Analysis
Component Complexity Connector complexity
Severity analysis Identifying failure modes. - failures modes of Individual components. - failure modes of individual connectors. Conducting Effect Analysis. Ranking severity.
Catastrophic Critical Marginal Minor.
Develop Reliability Risk Factors for Architecture Elements
Heuristic Factor for a component
Heuristic factor for a connector.
Developing Component Dependency Graphs
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
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 - Sequential execution
Conclusion
Applicable to architecture level so the errors can identified and detected at the early stages of life cycle.
Based on dynamic metrics . Automatable.
References 1. Volume: 28, Issue: 6, Year: Jun 2002
A methodology for architecture-level reliability risk analysisYacoub, S.M.; Ammar, H.H.Page(s): 529-547
2. 1 Architectural-level risk analysis using UMLGoseva-Popstojanova, K.; Hassan, A.; Guedem, A.; Abdelmoez, W.; Nassar, D.E.M.; Ammar, H.; Mili, A.;Software Engineering, IEEE Transactions on , Volume: 29 , Issue: 10 , Oct. 2003 Pages:946 – 960
3. 7 Risk analysis-a subjective processRedmill, F.;Engineering Management Journal , Volume: 12 , Issue: 2 , April 2002 Pages:91 – 96