of the software is executed, the greater the percentage of test cases that should be allocated to that function or subset. Types of reliability testing Software reliability testing includes feature testing, load testing, and regression testing. Feature test Feature testing checks the features provided by the software and is conducted in the following steps: Each operation in the software is executed once. Interaction between the two operations is reduced and Each operation is checked for its proper execution. The feature test is followed by the load test. Load test This test is conducted to check the performance of the software under maximum work load. Any software performs better up to some amount of workload, after which the response time of the software starts degrading. For example, a web site can be tested to see how many simultaneous users it can support without performance degradation. This testing mainly helps for Databases and Application servers. Load testing also requires software performance testing, which checks how well some software performs under workload. Regression test Regression testing is used to check if any new bugs have been introduced through previous bug fixes. Regression testing is conducted after every change or update in the software features. This testing is periodic, depending on the length and features of the software. Test planning Reliability testing is more costly compared to other types of testing. Thus while doing reliability testing, proper management and planning is required. This plan includes testing process to be implemented, data about its environment, test schedule, test points, etc. Problems in designing test cases Some common problems that occur when designing test cases include: Test cases can be designed simply by selecting only valid input values for each field in the software. When changes are made in a particular module, the previous values may not actually test the new features introduced after the older version of software. There may be some critical runs in the software which are not handled by any existing test case. Therefore, it is necessary to ensure that all possible types of test cases are considered through careful test case selection. Reliability enhancement through testing Studies during development and design of software help for improving the reliability of a product. Reliability testing is essentially performed to eliminate the failure mode of the software. Life testing of the product should always be done after the design part is finished or at