Test Case Design: Techniques & Key Influences
The use of test cases in agile software development is an intensely debated topic. While some teams vouch for it as a tool for better quality management, others consider it to be a waste of time and resources. In my view, test cases cannot be completely removed; instead, they must be handled on a case-by-case basis. For business-to-business enterprise solutions, software with intricate capabilities, such as taxation, critical applications, such as medical equipment, teams with migratory members, handover projects, etc., test cases is quite helpful.
While there is no one size fits all answer, it is important to acknowledge that the test case design also offers a creative space for the test engineering team. Numerous test case design methodologies exist, and in this blog, let us discuss a handful of the most popular ones currently available.
Test Case Design Based on Test Data
This method involves comparing the application's output to predetermined input and expected outcomes. At its core, this strategy is extremely straightforward, and there are numerous ways to evaluate an interactive field.
Boundary Value Analysis
This approach to test cases focuses on evaluating the upper and lower bounds of input values. The method seeks to find possible flaws or faults that could appear at the margins of input ranges. In order to ensure that the system responds appropriately in challenging border circumstances, test cases are created to cover both valid and invalid boundary values. Range-based input validations are the right places where this approach can be implemented.
Example: An age field in a form
Decision table testing
This approach to test cases is appropriate for systems having a variety of situations and accompanying actions. A decision table is made, recording several arrangements of circumstances and steps. The system's decision-making abilities are then thoroughly tested by creating test cases that cover every potential combination. This method aids in finding faulty or missing reasoning in decision-making processes. Validating business rules and validations are a very good example of where decision table testing can be applied.
State transition testing
When the system has several states and transitions between them, this method of creating test cases is used. This method seeks to verify that the system handles state-dependent functionality adequately and transitions between states reliably and consistently. In order to validate the system's behavior under changing states, test cases are created to cover a variety of state transitions, including both legitimate and invalid transitions.
This approach to test cases is a method that relies on the tester's knowledge and instinct about potentially vulnerable spots in the system. Test cases are created with those regions in mind, testing potential mistake scenarios that other methodologies might not cover. To find hidden flaws or vulnerabilities in the system, this technique depends on the tester's critical and inventive thinking skills
Test Case Design Based on The Test Approach
This is a method for testing software that places a focus on concurrent learning, test design, and test execution. It entails studying the behavior of the system that is being tested and quickly finding any potential problems or areas for improvement. Exploratory testing uses the tester's abilities, intuition, and domain knowledge in place of planned test cases to find flaws and learn about the system's behavior.
This kind of test case design is appropriate for situations in which the application is less complex or less crucial, or for long-lasting teams with high levels of collaboration and ability. Finding an exit point can be a little challenging because no limit is expressly specified.
This is a method for testing software that makes use of models to create, produce, and run test cases. In MBT, a model is built to depict the functionality, behavior, or structure of the system being tested. The model is used as a guide to create test cases that span many paths, scenarios, and input combinations.
This involves creating a model of the system as a finite-state machine (FSM) and designing test cases to cover different paths and scenarios within that model. To successfully apply State-Based Testing, testers should have a good understanding of the system and its expected behavior in different states. Collaboration between testers, developers, and domain experts is crucial to accurately represent the system's states and transitions in the state model.
Test Case Design Based on Test Executions
With this method, test cases are created and prepared with the new feature under development in mind. Test cases handled the feature as a complete stand-alone functionality and covered both positive and negative scenarios. This method has been widely used by modern test engineering teams since it appears to provide them with a strong handle on requirement traceability and other quality metrics. The only downside of this approach
Process integration testing
This is an approach to integration testing; test cases created using this approach center on E2E user flows. Such test cases primarily seek to demonstrate to a tester how to approach an application as a whole, rather than merely a single feature. Process integration test cases (PIT) only cover the "happy path," leaving testers' imaginations free to construct additional scenarios. This methodology is widely used in Large enterprise organizations, and the application enhancements are tested at different levels for their validity.
Test cases are created to execute user acceptance tests, where the testers are mostly stakeholders. These kinds of test cases give a good preview of the application's latest enhancements, specifications, and dependencies that must be met in order to complete the test case. Since many teams reuse feature test cases, acceptance test cases are not commonly used.
Factors Influencing The Test Cases
Test cases are dynamic documents that are updated and changed frequently. In some cases, it could also need to make room for features that are being retired and changes to how applications behave. The following criteria have a direct impact on test cases regardless of the approach used to build them.
- Risks or Threats: If new risks or threats are found in the system, additional or updated test cases may be needed to address these areas, necessitating the adjustment of unconventional test case creation methodologies.
- Complex System Enhancements: Non-conventional test case design methodologies may need to be modified to address the increased complications if the system goes through considerable alterations or architectural revisions.
- Versioning: Although the need for applications is continually changing, not all users will be willing to spend consistently upgrading to the most recent version. Most B2B applications require interoperability since different UI and DB versions must work together and vice versa.
- Evolving Requirements: When the requirements change over time, the test cases must adapt to account for these changes by making sure they cover the intended functionality and are in line with the evolving needs.
- Feedback and Results: Feedback and findings from unconventional testing methods may have an impact on test case revisions. Modifications for better coverage or efficacy can result from the lessons learned from earlier test executions.
Comprehensive testing and ensuring the quality of software products require effective test case design. Techniques for designing test cases include Equivalence Partitioning, Boundary Value Analysis, Decision Table Testing, State Transition Testing, Use Case Testing, and Error Guessing. The dynamic nature of software development, however, necessitates routine examination and modification of test cases.
Some of the major causes affecting test case modification are changes in requirements, bug corrections, system improvements, environmental changes, code updates, and test case optimisation. It is essential for efficient and effective testing, which ultimately results in greater software quality and customer happiness, to adapt and evolve test cases in response to these circumstances.