Reliability testing is a testing process that aims to measure the reliability of a system. You can check in the reliability testing process if the system has achieved that required reliability level. The process of measuring the reliability of a system is illustrated in Figure.
This process involves four stages:
1. You start by studying existing systems of the same type to understand how these are used in practice. This is important as you are trying to measure the reliability as it is seen by a system user. Your aim is to define an operational profile. An operational profile identifies classes of system inputs and the probability that these inputs will occur in normal use.
2. You then construct a set of test data that reflects the operational profile. This means that you create test data with the same probability distribution as the test data for the systems that you have studied. Normally, you will use a test data generator to support this process.
3. You test the system using these data and count the number and type of failures that occur. The times of these failures are also logged.
4. After you have observed a statistically significant number of failures, you can compute the software reliability and work out the appropriate reliability metric value.
