A method and system for improving the reliability of a system, such as a software system, is disclosed. "Service measurements" that are routinely measured and monitored in connection with the operation of systems (e.g., QOS (Quality Of Service) measurements) are utilized in the reliability architecture of the system. Service measurements include a number of alternative data types, such as transactions completed, messages received, messages sent, calls completed, bytes transmitted, jobs processed, etc. Any operations of the system that are typically monitored for other purposes can be utilized in the reliability architecture of the present invention. Most systems track these types of statistics as, for example, part of their billing procedures or part of their performance bench-marking or QOS processes. Since these statistics are already kept, it is very simple to analyze the statistics to create the historical signatures, and then monitor the statistics of the currently operating system to perform the signature checking process.