How to fix software bugs: Guide and best practices
'An ounce of prevention is worth a pound of cure.' -- Benjamin Franklin, 1736. The original quote pertained to fire safety, but it still applies to software bug prevention today.
Despite a development team's best intentions, software bugs happen.
Bugs are coding errors that the user experiences. When bugs are present, the user might experience performance issues, incorrect application behaviors, application freezes or complete crashes. They can be present anywhere within an application codebase and might include security issues, errors in API code or database problems.
In general, bugs interrupt a customer's ability to get work done with an application. They can vary in severity from a minor customer annoyance to a complete crash or freeze that causes customers to perform rework.
Developers often respond to bugs by entering them as enhancement requests in response to customer feedback. It's always preferable to identify bugs during development rather than respond after customers experience issues. Still, regardless of the development team's best prevention efforts, some bugs will manifest.
Because absolute prevention isn't possible, software development teams must understand how to fix software bugs to prevent recurring errors.
10 best practices for fixing bugs
Development teams must create best practices to ensure bug fixes follow a detailed process to prevent future occurrences. Ideally, once a team fixes a customer bug, the same bug is never experienced by another customer.
Best practices for fixing bugs include the following.
1. Diagnose the bug and trace it to a root cause
When a user identifies a defect, developers need to debug the code and trace the error back to the root cause. Otherwise, the bug fix might only repair a symptom rather than fixing the bug completely.
2. Replicate the bug in a test or development environment
Reproducing a bug in a test or development environment helps determine the root cause. Some bugs are the result of differences in application settings or even platforms. Developers fix bugs more effectively when they can reproduce the error and fully debug the issues.
3. Consider using automated testing tools with AI technology to find bugs fast
AI technology provides a rapid means of identifying defects during the development cycle. Many modern automated testing tools include AI technology to help teams identify defects and write tests, such as unit tests. Most also include the ability to execute tests in parallel to save time and reduce rework.
4. Collaborate to identify the bug and test repair options
Building active collaboration habits between development team members helps get customer-reported bugs fixed rapidly and accurately. Talking through defects together also improves repair options by brainstorming design and coding options.
5. Retest all bug fixes before releasing the new build to production
Always test bug fixes in a test environment before creating or releasing a new build to customers. Modern applications are complex and often highly integrated. Retesting helps reduce any new bugs generated by a fix. Regardless of how fast the team applies a fix and generates a new build, the customer will not be satisfied if a fix introduces a new bug.
6. Update test cases so that any reoccurrence of a bug is identified in future testing
7. Add unit or coded testing to identify the bug internally should it reoccur
Development teams must create unit tests for production bug fixes or add coded test scripts into existing build verification suites. Including a test prevents the bug from reaching customers again by identifying it before a test build is created.
8. Once tests are developed and the fix is confirmed, push the application code to production
Once all test cases for the bug have passed, developers create a new build and move it to a test server for smoke and regression testing. Executing smoke and regression testing identifies any other bugs that may have been created with the fix. Always plan time to test bug fixes by running a full smoke and regression test, as this prevents customers from experiencing additional bugs or bug repeats in new builds.
9. Once the bug passes internal testing, contact the customer and request a retest
Most customers retest bugs from new builds. Request feedback on the customer's retest. Wait for customer feedback to verify the fix meets their needs before closing out the bug.
10. Distribute feedback to the rest of the team
Development teams must continuously improve the production bug process to avoid repeat occurrences. When the team reviews the iteration or release, make it a point to discuss all customer-reported bugs and fixes as a team training initiative. Customer feedback on bug fixes is critical to supporting positive UX for the application.
As a final step, verify the bug record documents all testing results and customer feedback, along with a link to the current test cases.
How to prevent software bugs
Production bugs can cause a team crisis if unplanned. Imagine the time-consuming chaos that occurs whenever a critical bug is reported. First, news of the bug reaches upper management and then explodes throughout the development team. The first question is always: How did testing miss it? This is followed by assigning a developer and attempting to rush the fix into production.
The more integrated and complex the application, the more likely it is that bugs will pop up at connection points.
Application code always has bugs if more than one developer is involved. Application complexity can also cause bugs. The more integrated and complex the application, the more likely it is that bugs will pop up at connection points, such as when data is saved to a database or transferred to an API. Bugs are inevitable, but there are steps development teams can take to prevent them.
The trick to preventing bugs from reaching customers starts with planning and continues through team communication and collaboration. Creating a plan to manage customer-reported bugs from production means that, should a bug occur, the team knows the process and wastes less time in bug chaos and confusion.
Steps to prevent software bugs include the following.
1. Create a strategic plan that includes how the team manages customer-reported bugs
Production bugs interrupt existing work and can throw an iteration off track if not managed or planned. Teams constantly interrupted with fixing and testing bug fixes fall behind schedule with planned work. Avoid the bug fix circus by creating a plan to manage bugs specifically coming from production.
2. Adopt and use coding standards
Development teams must start by selecting coding standards -- sets of rules or guidelines for writing, building, deploying and testing code. Coding standards make the debugging process easier. Standards differ by team, organization and development methodology. They can be as simple as a checklist of rules or more complex with detailed samples of code comments and organization. Overall, practicing organized and consistent development helps build quality into the code at the start.
3. Build testable code and include unit tests
Testing starts with developers building unit tests or other coded automated testing. Applying unit or automated integration tests to new builds helps teams identify errors before they are included in a test build.
4. Build in quality, starting with development and continuing with a formal testing strategy
Testing starts in development and then continues with a formal testing strategy or plan.
5. Perform code reviews between developers
Code reviews help detect errors and fix them before they must be tracked. Defects found during review save time and reduce duplicate work.
6. Fully test and debug all code in development before checking it into a build
Be sure to plan in development time for testing and debugging before application testing moves to the QA testing team.
7. Use QA testing methodologies, including automated and manual testing
When creating team processes, include unit and integration tests, and schedule frequent automated test execution. Modern AI-enhanced tools often include the ability to create unit tests and provide other valuable testing features. Teach the QA testers to create automated tests and manage them to reduce the developer workload and improve testers' skills.
8. Develop test cases for every customer defect and execute regular, planned testing
Ensure the QA testing team creates new test cases to cover all production bugs and includes them in planned regression or smoke testing before a build is released.
9. Track defects for historical reference and documentation
Use a defect tracking tool to manage and document every production defect. Defects provide valuable history and help teams learn where defects tend to occur and how to fix them.
10. Learn from bugs by discussing the bug and its root cause within the team
Make it part of the team's standard process to discuss every production bug, its root cause and the fix applied during review or planning meetings. Be sure everyone understands the importance of limiting customer exposure to any bug. Support communication and team collaboration to better protect customers from defects and development teams from bug circus chaos. Keep developers' and testers' skills up to date, and provide them with tools that help test effectively throughout the entire SDLC.
Bugs can be identified, fixed and prevented at every step of the SDLC.
Amy Reichert is a 25-plus-year professional QA tester and writer. As a tester, she specializes in test development and Agile team management.
