Types of software testing

There are many different types of software tests, each with specific objectives and strategies:

• Acceptance testing: Verifying whether the whole system works as intended.
• Integration testing: Ensuring that software components or functions operate together.
• Unit testing: Validating that each software unit performs as expected. A unit is the smallest testable component of an application.
• Functional testing: Checking functions by emulating business scenarios, based on functional requirements. Black-box testing is a common way to verify functions.
• Performance testing: Testing how the software performs under different workloads. Load testing, for example, is used to evaluate performance under real-life load conditions.
• Regression testing: Checking whether new features break or degrade functionality. Sanity testing can be used to verify menus, functions and commands at the surface level, when there is no time for a full regression test.
• Stress testing: Testing how much strain the system can take before it fails. Considered to be a type of non-functional testing.
• Usability testing: Validating how well a customer can use a system or web application to complete a task.

In each case, validating base requirements is a critical assessment. Just as important, exploratory testing helps a tester or testing team uncover hard-to-predict scenarios and situations that can lead to software errors.

Even a simple application can be subject to a large number and variety of tests. A test management plan helps to prioritize which types of testing provide the most value – given available time and resources. Testing effectiveness is optimized by running the fewest number of tests to find the largest number of defects.