Which of the following is NOT a component of testing?

Testing is a comprehensive process that evaluates software quality through various methodologies and techniques. The components of testing generally involve checking the internal workings of an application, performance aspects, and how the software handles various input scenarios.

Branch coverage and decision tables are both tools and methodologies used in testing. Branch coverage is a code coverage metric that ensures that all possible paths (branches) of conditional statements have been executed, thus validating the logic in the code. Decision tables, on the other hand, provide a systematic way of representing and testing complex business rules and different input combinations. These are integral to ensuring that all scenarios are considered during testing.

In contrast, checking for memory leaks and robustness is more about evaluating the software's performance and stability under certain conditions rather than a formal testing component or methodology. Memory leak testing often falls under performance testing, which is concerned with how efficiently the software operates, while robustness testing focuses on how well the software can handle errors or unexpected situations.

Thus, decision tables, while valuable tools in testing, are categorized differently from the main components of testing in the context of this question. Hence, choice related to decision tables is identified as not being a direct component of testing itself.