Tech Insights
How to Nail Your Test Cases Every Single Time
Writing effective test cases (TCs) sometimes feels like putting together a tricky jigsaw puzzle. Even those of us with extensive experience in quality assurance services often encounter the same problems repeatedly. Whether you’re new to testing or have been doing it for a while, knowing how to create and run test cases well can really make your work shine. In this article, we’ll go through some tips and tricks to help you avoid common mistakes and get your test cases right every time. Let’s get started and make testing a whole lot easier!
How to Write Effective Test Cases
Everyone has their own way of doing things, so copying someone else’s method might not work for you. Also, it’s hard to ensure your method covers all your requirements without leaving any gaps. To help you, we’ve prepared a few pointers for writing effective test cases in software testing.
Decide What You Want to Test
Before you start writing software test cases, create a simple checklist or list the most important things you need to test. This helps you focus on what’s crucial. Then, split the cases into smaller parts to make it easier to organize your tests and group cases into test scenarios.
BEST PRACTICE
- Add a label or component to your TC — it will help you extract cases from the necessary module
- Prioritize your TCs — this will help you find a set of the most critical cases
Keep These Test Design Techniques in Mind
The following test design techniques will help you save time, provide thorough test coverage, and test your application deeply and logically (based on ISTQB Glossary):
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Equivalence Partitioning
This is a black-box test design technique in which test cases are designed to run representatives from equivalence partitions. In principle, test cases are designed to cover each partition at least once.
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Boundary Value Analysis
This is another black-box technique where test cases are designed based on boundary values. BVA focuses on testing at the edges between partitions. If you’ve done range checking before, you’ve likely used this technique even if unknowingly. Note that we cover both valid boundaries (in the valid partitions) and invalid boundaries (in the invalid partitions).
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Decision Table Testing
A black-box test design technique in which test cases are designed to run all possible combinations of conditions and the resulting actions shown in a decision table. A decision table is an excellent way to deal with combinations of things (e.g., inputs). This technique is also sometimes referred to as a “cause-effect table.” This is because there is an associated logic diagramming technique called “cause-effect graphing,” which is sometimes used to help derive the decision table.
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Use Case Testing
This is a black-box test design technique in which test cases are designed to exercise use case behaviors. It helps us identify test cases that exercise the whole system using business user scenarios and identify gaps in software applications that might not be found by testing individual components.
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State Transition Testing
A black-box test design technique in which test cases are designed to exercise elements of a state transition model. It’s particularly effective when the system has a finite number of states. One of the advantages of the state transition technique is that the model can be as detailed or abstract as needed. When part of the system is more important (i.e., requires more testing), a greater depth of detail can be modeled.
BEST PRACTICE
Analyze your software model and select one or more of these test design techniques to create your tests.
Use a Requirements Traceability Matrix in Testing for Visibility
To understand how to write effective test cases, it’s better to visualize the state of test coverage and see the relationship between requirements and test cases. Use a document (preferably a table) that maps and traces user requirements with test cases. This is known as a requirements traceability matrix for testing. It will demonstrate which requirements are not covered by test cases, and show you areas with excess or insufficient testing.
BEST PRACTICE
Fill in your traceability matrix with direct links to specification items and test cases, as well as the most specific and critical bugs you come across.
Make TCs Complex but Simple
A test case should contain all necessary details, relevant artifacts, and GUIs to avoid going through a pile of documents to complete a single test scenario. Test cases should be grouped into test suites in logical order. At the same time, a test case should be well-structured so that it is easy to understand and execute. All the steps for each TC should be atomic, in the correct sequence, and reflect test data relevant to these input values.
BEST PRACTICE
It’s better to have a project TC template and build test cases in one style across the whole project.
Review Your Own and Your Teammates’ TCs
Once you have written the last TC of the test suite, go back to the beginning and review all TCs from the tester’s point of view. Make sure that all the steps you’ve mentioned are clear and that every step has an appropriate expected result.
BEST PRACTICE
Review TCs written by other testers. This will help you identify any uncertainty, mistakes, or gaps before testing.
Keep TCs Up to Date
Since requirements are constantly changing, you have to constantly update your test cases in your test executions. During execution, you may come up with new ideas, find new sub-conditions in a single TC, or even decide to add entirely new TCs. That’s why a periodic review and update of test scenarios will help to avoid the pesticide paradox and identify new bugs.
BEST PRACTICE
Link TCs to bugs and build new test cases if a TC does not already cover the issue you find.
Add Examples and Test Data
Provide a range of inputs as an example or attach prepared fields or documents as test data, especially where calculations are to be performed or the application’s behavior depends on inputs. By doing so, you’ll ensure that important test data isn’t ignored during the execution of TCs.
Distribute Test Cases Among Testers
Normally there are several testers who test different modules of a single application. TCs are divided among them according to the areas of application set to undergo testing. Some TCs related to the integration of an application may be executed by multiple testers, while others may be executed by only a single tester.
BEST PRACTICE
Remember to rotate test case execution for different areas between QAs for more effective testing and new perspectives.
Checklists Matter Too
Remember that TCs are not the only test documentation used for manual testing. Analyze the application’s size and business logic, project duration, team size, and customer expectations. Swap detailed test cases for efficient checklists in the case of small, straightforward projects or when resources are tight. Tailor your approach to fit project needs and ensure nothing falls through the cracks. One good practice is to have a checklist for specific verification that we run less often, but it is essential to have it as a list of checks.
BEST PRACTICE
Use a checklist for smoke/sanity tests on big projects with complex logic, even if detailed test cases exist. It also helps to concentrate on the most critical scenarios.
Sharp test cases, sharper teamwork
Manual testers should always ask themselves how they can write more effective test cases, as this greatly impacts the entire testing process. Writing test cases should be planned well in advance and completed in a well-organized manner. In addition to making your life easier, proper documentation will help your whole team, including the other testers, developers, BAs, and customers.
Did you know that enhancing the effectiveness of test cases and using techniques like boundary value analysis can reduce defects by up to 25%? So, remember to keep your test cases clear, comprehensive, and up-to-date to ensure high-quality software. Need expert help to optimize your test documentation? Our QA team is just a call away!
Author: Darya Adziarykha