Test Case Development

A test case is a detailed procedure that fully tests a feature or an aspect of a feature. While the test plan describes what to test, a test case describes how to perform a particular test. You need to develop test cases for each test listed in the test plan.

General Guidelines
As a tester, the best way to determine the compliance of the software to requirements is by designing effective test cases that provide a thorough test of a unit. Various test case design techniques enable the testers to develop effective test cases. Besides, implementing the design techniques, every tester needs to keep in mind general guidelines that will aid in test case design:

a. The purpose of each test case is to run the test in the simplest way possible. [Suitable techniques - Specification derived tests, Equivalence partitioning]

b. Concentrate initially on positive testing i.e. the test case should show that the software does what it is intended to do. [Suitable techniques - Specification derived tests, Equivalence partitioning, State-transition testing]

c. Existing test cases should be enhanced and further test cases should be designed to show that the software does not do anything that it is not specified to do i.e. Negative Testing [Suitable techniques - Error guessing, Boundary value analysis, Internal boundary value testing, State-transition testing]

d. Where appropriate, test cases should be designed to address issues such as performance, safety requirements and security requirements [Suitable techniques - Specification derived tests]

e. Further test cases can then be added to the unit test specification to achieve specific test coverage objectives. Once coverage tests have been designed, the test procedure can be developed and the tests executed [Suitable techniques - Branch testing, Condition testing, Data definition-use testing, State-transition testing]

Test Case – Sample Structure
The manner in which a test case is depicted varies between organizations. Anyhow, many test case templates are in the form of a table, for example, a 5-column table with fields:

Test Case ID
Test Case Description
Test Dependency/Setup
Input Data Requirements/Steps
Expected Results
Pass/Fail