Software Engineering - Old Questions

10. Explain the reliability validation with example. 

Reliability validation is the process of measuring the reliability of a system. To validate that the system meets these requirements, we have to measure the reliability of the system as seen by typical system user.

Reliability validation process:

  1. Establish the operational profile for the system.

  2. Construct test data reflecting the operational profile

  3. Test the system and observe the number of failures and the times of these failures.

  4. Compute the reliability after a statistically significant number of failures have been observed.

Difficulties in Reliability validation:

1. Operational profile uncertainty: The operational profiles based on experience with other systems may not be an accurate reflection of the real use of the system.

2. High costs of test data generation: It can be very expensive to generate the large volume of data required in an operational profile unless the process can be totally automated.

3. Statistical uncertainty when high reliability is specified: We have to generate a statistically significant number of failures to allow accurate reliability measurements. When the software is already reliable, relatively few failures occur and it is difficult to generate new failures.