Which principle of testing states that exhaustive testing is impossible?

The principle that states exhaustive testing is impossible is rooted in the concept that, due to the vast number of potential inputs, scenarios, and environments, it is not feasible to test every possible case or combination of inputs in a software application. This principle recognizes that testing involves making decisions about what to test based on risk, resource constraints, and time limitations.

In the context of testing principles, the Seven Principles of Testing encompass fundamental truths that guide effective testing practices. One of these principles clearly acknowledges that complete and exhaustive testing cannot be achieved. This is an important realization for testers as it directs them to focus on strategic testing approaches, prioritizing critical areas that are likely to yield the most valuable insights regarding the software's performance and reliability.

By understanding this principle, testers can better allocate their resources and shape their test strategies to address the most significant risks, ensuring that they can find defects efficiently without the unrealistic goal of testing every possible scenario. It encourages a more practical view of testing, embracing the idea of risk-based testing and targeted efforts rather than an all-encompassing approach that would be impractical and time-consuming.