Dependability and Survivability Evalution of a Water Distribution - PowerPoint PPT Presentation

Outline Water distribution model Arcade Survivability in Arcade Conclusions References Dependability and Survivability Evalution of a Water Distribution Process with Arcade Stephan Roolvink, Anne Remke, Mari¨ elle Stoelinga Performability Modeling of Computer and Communication Systems 2009 Stephan Roolvink, Anne Remke, Mari¨ elle Stoelinga Dependability & Survivability of a Water Distribution Process

Outline Water distribution model Arcade Survivability in Arcade Conclusions References 1 Water distribution model 2 Arcade 3 Survivability in Arcade 4 Conclusions Stephan Roolvink, Anne Remke, Mari¨ elle Stoelinga Dependability & Survivability of a Water Distribution Process

Outline Water distribution model Arcade Survivability in Arcade Conclusions References Distribution station Drinking water Reservoir 1 Drinking water Reservoir 2 district 1 pumping station Distribution station district 2 Stephan Roolvink, Anne Remke, Mari¨ elle Stoelinga Dependability & Survivability of a Water Distribution Process

Outline Water distribution model Arcade Survivability in Arcade Conclusions References Distribution station Valve 4 Valve 1 input 1 output 1 Valve 3 Tank input 2 Output 2 Valve 2 Valve 5 Valve 6 Stephan Roolvink, Anne Remke, Mari¨ elle Stoelinga Dependability & Survivability of a Water Distribution Process

Outline Water distribution model Arcade Survivability in Arcade Conclusions References Measures of interest Availability Reliability Survivability Stephan Roolvink, Anne Remke, Mari¨ elle Stoelinga Dependability & Survivability of a Water Distribution Process

Outline Water distribution model Arcade Survivability in Arcade Conclusions References Taxonomy of dependability Availability Availability is the probability of the system being in an operational state within a mission time assuming that components are repaired. Stephan Roolvink, Anne Remke, Mari¨ elle Stoelinga Dependability & Survivability of a Water Distribution Process

Outline Water distribution model Arcade Survivability in Arcade Conclusions References Taxonomy of dependability Reliability according to [Sanders and Malhis, 1992] Reliability is the probability of having no system failure within a certain mission time assuming that no component is repaired. Stephan Roolvink, Anne Remke, Mari¨ elle Stoelinga Dependability & Survivability of a Water Distribution Process

Outline Water distribution model Arcade Survivability in Arcade Conclusions References Taxonomy of dependability Survivability according to [Cloth and Haverkort, 2005] Survivability is the ability of a system to recover predefined service levels in a timely manner after the occurrence of disasters . survivability ≡ disaster ⇒ recoverability (1) recoverability ≡ P ≥ p ( true U ≤ t service ) (2) Stephan Roolvink, Anne Remke, Mari¨ elle Stoelinga Dependability & Survivability of a Water Distribution Process

Outline Water distribution model Arcade Survivability in Arcade Conclusions References What is Arcade (architectural dependability evaluation)? Basic building blocks Arcade Arcade UML AADL txt format graphical format Components Arcade Repair units parser Spare management unit XML Arcade conversion Defining measure of interest IO-IMC Fault tree style CADP format CADP Measures of interest Analysis results Availability Reliability Boudali et al. [2008] Stephan Roolvink, Anne Remke, Mari¨ elle Stoelinga Dependability & Survivability of a Water Distribution Process

Outline Water distribution model Arcade Survivability in Arcade Conclusions References What is Arcade (architectural dependability evaluation)? Basic building blocks Arcade Arcade UML AADL txt format graphical format Components Arcade Repair units parser Spare management unit XML Arcade conversion Defining measure of interest IO-IMC Fault tree style CADP format CADP Measures of interest Analysis results Availability Reliability Boudali et al. [2008] Stephan Roolvink, Anne Remke, Mari¨ elle Stoelinga Dependability & Survivability of a Water Distribution Process

Outline Water distribution model Arcade Survivability in Arcade Conclusions References What is Arcade (architectural dependability evaluation)? Basic building blocks Arcade Arcade UML AADL txt format graphical format Components Arcade Repair units parser Spare management unit XML Arcade conversion Defining measure of interest IO-IMC Fault tree style CADP format CADP Measures of interest Analysis results Availability Reliability Boudali et al. [2008] Stephan Roolvink, Anne Remke, Mari¨ elle Stoelinga Dependability & Survivability of a Water Distribution Process

Outline Water distribution model Arcade Survivability in Arcade Conclusions References I/O-IMC (Input/Output Interactive Markov Chain)  0 1 Finite-state machine up! fail! 3 types of transitions Markovian transitions 2 Direct-action transitions 3 repair? Delayed-action transitions repair! 0 1  Stephan Roolvink, Anne Remke, Mari¨ elle Stoelinga Dependability & Survivability of a Water Distribution Process

Outline Water distribution model Arcade Survivability in Arcade Conclusions References I/O-IMC (Input/Output Interactive Markov Chain)  0 1 Finite-state machine up! fail! 3 types of transitions Markovian transitions 2 Direct-action transitions 3  Delayed-action transitions Stephan Roolvink, Anne Remke, Mari¨ elle Stoelinga Dependability & Survivability of a Water Distribution Process

Outline Water distribution model Arcade Survivability in Arcade Conclusions References Distribution station model - parameters Rates are assumed values (work in progress) Failure rates: λ valve open = λ valve close = 1 / 2000 and λ tank = 1 / 6000 Repair rates: µ valve = 1 and µ tank = 5 / 60 Assumption: stuck open cannot cause a system failure Model uses dedicated repair units Stephan Roolvink, Anne Remke, Mari¨ elle Stoelinga Dependability & Survivability of a Water Distribution Process

Outline Water distribution model Arcade Survivability in Arcade Conclusions References I/O-IMC of Distribution station model  valve − close  tank 0 1 0 1  valve − open UP tank ! FAIL tank ! UP valve ! FAIL − C valve ! 2 2 3  valve 3  tank (a) Valve I/O-IMC (b) Tank I/O-IMC Stephan Roolvink, Anne Remke, Mari¨ elle Stoelinga Dependability & Survivability of a Water Distribution Process

Outline Water distribution model Arcade Survivability in Arcade Conclusions References Fault tree (for availability and reliability) Valve1 Valve2 Valve3 Valve4 Valve5 Valve6 Tank Stephan Roolvink, Anne Remke, Mari¨ elle Stoelinga Dependability & Survivability of a Water Distribution Process

Outline Water distribution model Arcade Survivability in Arcade Conclusions References Distribution station model - Availability over time Availability 1 0.98 0.96 Probability (A) 0.94 0.92 0.9 0.88 0.86 0 500 1000 1500 2000 2500 3000 3500 4000 t in hours Steady state availability 0.84 Stephan Roolvink, Anne Remke, Mari¨ elle Stoelinga Dependability & Survivability of a Water Distribution Process

Outline Water distribution model Arcade Survivability in Arcade Conclusions References Water distribution Model - Reliability over time Reliability 1 0.9 0.8 0.7 Probability (R) 0.6 0.5 0.4 0.3 0.2 0.1 0 500 1000 1500 2000 2500 3000 3500 4000 t in hours Stephan Roolvink, Anne Remke, Mari¨ elle Stoelinga Dependability & Survivability of a Water Distribution Process

Outline Water distribution model Arcade Survivability in Arcade Conclusions References Extending Arcade for survivability Needed to calculate survivability: Status information of components Disable lumping in CADP (generates state space explosion) Add atomic properties to states. Continuous Stochastic logic (CSL) model checking Export CADP model to MRMC model checker Stephan Roolvink, Anne Remke, Mari¨ elle Stoelinga Dependability & Survivability of a Water Distribution Process

Outline Water distribution model Arcade Survivability in Arcade Conclusions References Extending Arcade for survivability Needed to calculate survivability: Status information of components Disable lumping in CADP (generates state space explosion) Add atomic properties to states. Continuous Stochastic logic (CSL) model checking Export CADP model to MRMC model checker Stephan Roolvink, Anne Remke, Mari¨ elle Stoelinga Dependability & Survivability of a Water Distribution Process

Outline Water distribution model Arcade Survivability in Arcade Conclusions References Extending Arcade for survivability Needed to calculate survivability: Status information of components Disable lumping in CADP (generates state space explosion) Add atomic properties to states. Continuous Stochastic logic (CSL) model checking Export CADP model to MRMC model checker Stephan Roolvink, Anne Remke, Mari¨ elle Stoelinga Dependability & Survivability of a Water Distribution Process