Test plan vs test case (and why you need both)

Poor software doesn’t provide value to users. It causes customers to complain, cancel services, and return products. Flops like this can lower stock prices and lead to serious reputational damage. And they cost US businesses a massive $2.8 trillion.

Software testing is crucial for releasing products that are valuable to the end user and the bottom line. But to guarantee that each testing phase is as rigorous as possible, you need test plans and test cases.

What is a test plan?

A test plan is an in-depth document that catalogs the objectives, resources, and processes for testing a software product. It should include which teams or individuals are responsible for the testing and provide a detailed overview of the upcoming workflow.

The test plan isn’t just for testers, however. Because it gets updated regularly while the testing is active, it’s useful to all stakeholders and departments that need to follow the progress of the project.

What is a test case?

A test case provides step-by-step instructions on how to test if the software is working correctly. It’s used to assess the performance of features and determine if the product meets all requirements. It’s also used to detect bugs and vulnerabilities for teams to fix before the final release.

A test case is specifically for the testing team to use. They outline the inputs, actions, and responses needed to categorize the feature as satisfactory. Usually, they will use two types of test cases, one with valid input data and the other with invalid input data.

The benefits of writing a test plan

Think of a test plan as the foundation of your testing efforts. It tells you what you need to execute, as well as how. The benefit of having a testing plan is that it provides:

• Up-to-date information including the most recent test results and changing requirements
• A history of the tests executed and their results
• A detailed overview of the testing so all stakeholders can follow the progress of a project

The benefits of writing test cases

If the test plan is your foundation, the test cases are the building blocks. And while they’re specifically for the testing teams’ use, they benefit the entire organization by providing:

• Step-by-step guidance for guaranteed good test coverage
• Examples of how the software should function
• Results of how the software behaved during the test so developers can identify any failures
• Demonstration of the real-world value of the software features

The different types of test cases

Just as there are many different types of testing, there are many types of test cases. Let’s take a look at some of them and what purpose they serve:

• Unit test cases analyze individual units of the software to confirm each one performs as it should
• Functionality test cases determine if the functions are consistent with user expectations
• Performance test cases help validate response times
• Integration test cases determine how the different modules interact
• User interface test cases can verify if elements of the graphical user interface (GUI) perform as they should
• Security test cases check for vulnerabilities and ****confirm that the software restricts permissions

There are all manner of test cases, some requiring more technical skill than others. Some will require a fresh approach each and every time, while others you can reuse for easier execution next time around.