Test scenario vs Test cases: understanding the subtilities

In the intricate world of software testing, where the ultimate goal is to ensure the quality and reliability of an application, two essential components stand out: test scenarios and test cases.

They are fundamental to the testing process, allowing testers to systematically verify that the software meets desired standards and performs as expected.

However, despite their critical role, confusion often arises between these two pillars of testing documentation. In this article, we’ll delve into the nuances of test cases and test scenarios, exploring their definitions, purposes, and differences.

What is a test scenario?

A test scenario provides a high-level overview of a particular testing situation. It outlines the context within which testing will take place, describing the objectives, preconditions, and expected outcomes of the testing effort. Put simply, it defines what to test, delineating the end-to-end steps a tester would take to ensure that an application functions as intended.

Test scenarios are tailored to mimic real-world user experiences. For instance, when testing the process of purchasing a plane ticket, a test scenario would encompass every step from selecting a flight to completing the payment transaction.

The primary goal of test scenarios is to provide thorough coverage of the software’s functionality, empowering testers to verify the seamless integration and interaction of various features and components.

What is a test case?

Unlike test scenarios, test cases, serve as detailed instructions aimed at verifying specific functionalities of the software across various scenarios. Using test cases, testers can assess whether the application behaves as expected. They can assess what to test and how to test it. If we take our plane ticket example, the test cases to purchase it would cover the following steps: navigate to the booking page, input travel details, select a flight, enter payment information, and confirm the booking.

Other example to register a new user on a website: it would involve steps to navigate to the registration page, input user details, verify email confirmation, and log in with the newly created credentials.

Key elements of a test case include:

• test case ID
• description
• test data
• steps to reproduce
• test priority / severity
• expected results
• actual results

The primary purpose of test cases is to enable testers to identify defects or bugs within a narrow scope and ensure the correctness of individual functionalities. Test cases are integral to software testing as they offer comprehensive coverage of the system, allowing clients to understand how the product behaves and where defects are found, thus guiding their attention and efforts effectively.

What are the main differences?

To illustrate the difference between test cases and test scenarios, let’s draw an analogy to the world of filmmaking. A movie scenario can be likened to the overall plot and theme of a movie, outlining the general sequence of events, character motivations, and key plot points. Similarly, a test scenario provides a high-level overview of the testing objectives, conditions, and expected outcomes, setting the stage for the testing effort.

On the other hand, a movie script delves into the detailed execution of the movie scenario, providing specific instructions for each scene, dialogue, and action sequence. Likewise, a test case breaks down the test scenario into precise steps, specifying the actions to take, inputs to provide, and expected outcomes to verify.

Among the differences, we can list:

Scope: Test cases target specific functionalities, inputs or conditions while test scenarios have a broader scope covering multiple functionalities or use cases.

Focus: Test cases typically delineate both what to test and how to test, providing step-by-step procedures for verification. Test scenarios primarily identify what to test, pinpointing specific aspects of the software for evaluation.

Source: Test cases are derived from test scenarios, while scenarios are based on different documentations, including user stories and requirements so test scenarios come first in the process.

Ambiguity: Test scenarios are often summarized in one line. Because of it, test scenarios can sometimes be ambiguous and open to interpretation whereas detailed test cases minimize ambiguity ensures that testers have clear guidance on how to execute the testing tasks effectively.

Reusability: While test cases can be reused within similar contexts of creation or for regression testing, they may require adaptation for use in different scenarios. Test scenarios are more reusable across different projects.

Collaboration on test cases involves testers working closely with developers to refine and validate specific functionalities. It may not always include input from all the stakeholders while test scenarios encourage input from different departments and disciplines to discuss user scenarios, business requirements, etc.

In conclusion, while test cases and test scenarios represent distinct approaches to software testing, they are intricately connected within the testing process. This interconnected relationship outlines the importance of both test cases and test scenarios in ensuring the quality and reliability of software products.