Final answer:
The Test Summary Report should explain variances between planned and actual tests, found and fixed defects, and executed versus total test cases to provide insights into test coverage, product quality, and adherence to the test plan.
Step-by-step explanation:
The variances that should be explained in the Test Summary Report are the variances between what was planned for testing and what was actually tested. These variances provide insights into the test coverage and whether all planned test scenarios were completed. Explaining these variances can help stakeholders understand any risks associated with areas of the software that may not have been thoroughly tested. Additionally, understanding the variances between the defects found and the defects fixed is crucial, as it reflects the quality of the product and areas that may need further attention. The differences between the test cases executed and the total number of test cases are also significant as they may indicate deviations from the test plan. Lastly, while not as commonly important as the others, variances between the weekly status reports and the test exit criteria could be discussed if they provide meaningful information regarding the test process and its completion.