There is no DEFINITIVE answer to this question. Testing is not absolute and has no limits. However, we can use risk metrics (risk based testing) to IDENTIFY the likely scenarios that can cause the most harm or the sections of the software that is mostly used so that we focus our time and effort to the sections that are most IMPORTANT.

Testing should provide enough information about the status or health of an application, so the STAKEHOLDERS can make INFORMED decision on whether to release the software or spend more time on testing.

There is no definitive answer to this question. Testing is not absolute and has no limits. However, we can use risk metrics (risk based testing) to identify the likely scenarios that can cause the most harm or the sections of the software that is mostly used so that we focus our time and effort to the sections that are most important.

Testing should provide enough information about the status or health of an application, so the stakeholders can make informed decision on whether to release the software or spend more time on testing.