Share 'Your perception of reliability and statistical approach for the same'

Hello All,  Suggest your preception for software reliability and statistical approach to measure and forcast the changes (consider Pros and Cons).  Please dont consider this one as practical approcach, I need genearic inputs where we can follow a procedure to track the changes and what can be impact in future realse and how can future release can be tested. This e.g. is for maintenance project. …