In our earlier post, we made discussion on “Test Specification and Test case template”. Now we shall discuss about “Types of Test Cases: Formal and Informal Requirement Based Test Cases”.
Types of Test Cases
We can categorize test cases into following major types. These are
- Formal Test Cases
- Informal Test Cases
- Positive Test Cases
- Negative Test Cases
- Functional Test Cases
- Non-Functional Test Cases
- User Acceptance Test Cases
In this article we’ll discuss only two types of test cases i.e. Formal and Informal Requirement Based Test Cases.
Description of Requirements-Based Testing
A requirements-based testing methodology begins with requirements management. Business analysts, business users, product managers and others compile and manage requirements and specification documents as an accurate and complete description of the needs of the system. The QA department relies on these requirements as a basis to plan and execute their testing efforts. By tracking test planning and execution of test cases directly against the requirements, QA can confidently measure progress as the project evolves and ensure all requirements have been validated. When all requirements have been thoroughly tested, and the defects found during testing have been resolved, the QA department can provide formal release sign-off.
Formal Requirement Based Test Cases
In order to fully test that all the requirements of an application are met, there must be at least two test cases for each requirement: one positive test and one negative test; unless a requirement has sub-requirements. In that situation, each sub-requirement must have at least two test cases. Keeping track of the link between the requirement and the test is frequently done using a traceability matrix. Written test cases should include a description of the functionality to be tested, and the preparation required to ensure that the test can be conducted.
A formal written test-case is characterized by a known input and by an expected output, which is worked out before the test is executed. The known input should test a precondition and the expected output should test a post-condition.
Informal Requirement Based Test Cases
For application without formal requirements, test cases can be written based on the accepted normal operation of programs of a similar class. In some testing organizations, test cases are not written at all but the activities and results are reported after the tests have been run.
In scenario testing, hypothetical stories are used to help the tester think through a complex problem or system. These scenarios are usually not written down in any detail. They can be as simple as a diagram for a testing environment or they could be a description written in prose. The ideal scenario test is a story that is motivating, credible, complex, and easy to evaluate. They are usually different from those test cases in that test cases are single steps while scenarios cover a number of steps.
From the above discussion we can easily conclude that formal requirements based test cases are generated from formal requirements document. When there is no formal requirements document available then tester generates/writes test cases by using their experience about the working domain.
In our forthcoming post we’ll discuss “Types of Test Cases: Positive and Negative Test Cases”.
