Understanding the difference between the two becomes critical to perform testing more effectively and efficiently. Both test cases and test scenarios documents produced during the testing phase and offer stakeholders insights into testing progression . Let's take a granular look into what sets them apart.

A Case of Actionable Inputs vs. Real-World Requirements

A test case is a specific set of actions, instructions, or inputs employed to test particular functions or features of a software application. In concrete terms, it is a collection of conditions that testers use to determine application behavior and ascertain whether the feature or functionality behaves as expected.

Test cases emphasize actionable inputs, including positive, negative, and boundary values, to ensure exhaustive testing. As such, they contain details like steps to execute the test, test names, pre-and post-conditions of the tests, etc.

On the other hand, test scenarios are derived from use cases and account for the real-world scenarios where the software or application will be used. They provide a high-level overview of testing requirements and help categorize what's testable.

Writing test scenarios involves reading and addressing the software requirement documents and business function, system requirements, and functional requirement specifications. The test scenario must be related to the overall project in at least one significant way.

Ideally, a test scenario includes general descriptions of the steps that testers need to follow to test the function or feature. It defines the results that determine that an application works as expected.

Operational Validation vs. Functional Overview

Operational validation sits at the heart of test cases. To illustrate that, let's create a test case around the login functionality. If a tester has to validate the user login functionality, they have to stress the following steps and conditions:

On the contrary, test scenarios provide a functional overview of a feature or module, offering a broad perspective on what requires testing.

For instance, testing the search functionality of an eCommerce site represents a test scenario. It offers a high-level perspective of what needs validation. This test scenario constitutes multiple sample test cases, each focusing on the operational validation of different search keywords and related functionalities.

Strategic Timing in SDLC:

Test cases are for testing specific features or functionalities. So, it's prudent to write them early in the SDLC, such as during the requirements gathering phase. They should contain all the requirements, use case documentation, and the overall test plan. At the end of the day, the essence of writing test cases lies in ensuring comprehensive and meticulous testing.

Likewise, it's important to write test scenarios early in the SDLC. These can effectively gauge the testing footprint and ensure that all features and functionalities are covered for testing. Based on these scenarios, test cases are then formulated.

The test scenarios' objective is to check the entire system performance from the end-user point of view, imitating users' behavior and assessing the scale of the work. These have to account for the actual scenarios the application will experience and operate under after release.