1. CSE 322: Software Reliability Engineering Topics covered: Architecture-based reliability analysis

2. Introduction and motivation

3. Benefits of architecture-based analysis

4. Application architecture  Architecture:  Components:  Interactions:

5. Application architecture (contd..)  Sequential application:  Dynamic behavior:

6. Application architecture (contd..)  Types of applications:

7. Application architecture (contd..)  Models used:  Mapping of control-flow graph to models:

8. Application architecture (contd..)  Type of models:

9. DTMC analysis  Overview of DTMCs:  Absorbing:  Irreducible:

10. Analysis of absorbing DTMCs

11. Analysis of absorbing DTMCs (contd..)

12. Analysis of irreducible DTMCs

13. Example of architecture analysis Terminating application 10 modules 1 is the input, 10 is the exit module Architecture modeled by absorbing DTMC Probability that the control is transferred to module j, upon execution of module i 1 234 5 6 789 10

14. Example of architecture analysis (contd..) Intercomponent transition probabilities

15. Example of architecture analysis (contd..) Component 11.0000 0.0000 20.9077 0.6444 30.9107 0.5499 40.4184 0.3928 51.3504 0.7185 60.2510 0.2319 70.6155 0.6261 80.8737 0.4225 90.3831 0.2462 10 1.0000 0.0000 Mean number of visits Variance of the number of visits Computed for component i

16. Example of architecture analysis (contd..) Non-terminating application 10 modules Architecture modeled by irreducible DTMC Reliability of each component known Probability that the control is transferred to module j, upon execution of module i 1 234 5 6 789 10

17. Example of architecture analysis (contd..) Intercomponent transition probabilities Addition of two transitions to absorbing DTMC to make it irreducible

18. Example of architecture-based analysis (contd..) Component 10.1073 2 3 4 5 6 7 8 9 10 0.1055 0.1091 0.0765 0.1714 0.0459 0.0823 0.1129 0.0549 0.1341 Utilization of the component Computed for component i