1. CSE 221: Probabilistic Analysis of Computer Systems Topics covered: Analysis of software reliability and performance

2.  Motivation:  Two types of applications:

3. Terminating application  Definition:  Expected or average time taken for one run of the application:

4. Terminating application (contd..)  Example:  Control flow graph:

5. Terminating application (contd..)  Mapping control flow graph to DTMC:

6. Terminating application (contd..)  Transition probability matrix of DTMC:  Partition of matrix P, resulting in matrix Q:  Computation of fundamental matrix, M:

7. Terminating application (contd..)  Average number of visits to states:  Time spent in each module:  Average time to complete:

8. Non-terminating application  Definition:  Expected or average application reliability:

9. Non-terminating application (contd..)  Example:  Control flow graph:  Mapping control flow graph to DTMC:

10. Non-terminating application (contd..)  Computation of steady state probabilities:

11. Non-terminating application (contd..)  Steady state probabilities:  Module reliabilities:  Expected or average reliability of the application: