Defects — whether it be in the code or in the usability of a program — can be debilitating to any software project, potentially causing the entire initiative to fail. For this reason, testing must be able to identify these issues in order for quality assurance teams to mitigate them as early as possible. Many organizations have turned to QA automation for their testing methods, and with good reason — it can help catch bugs faster and more efficiently than ever before. Here are a few types of defects that automation is especially adept at detecting:

1) Issues That Have Appeared Before

Even if a specific bug doesn't appear more than once in a single project, it may appear in other app initiatives, meaning that QA will need to combat it again. With test automation tools, once a bug appears, the tests can be prepared to stop the issue in its tracks if it emerges again, programmer Alberto Gutierrez wrote on his blog Making Good Software. This guarantees that the same defect will never reappear undetected, allowing software quality assurance team members and developers to mitigate it early.

Although an automated test must be created for every new bug that is experienced, QA teams can reuse these cases to ensure that the issue is accurately identified and appropriately dealt with the first time. This eliminates a lot of the manual work that these professionals are used to doing when combating defects and enables them to easily eliminate the issue in future instances.

2) Usability and Accessibility Problems

While a computer may not be able to identify issues in usability and accessibility from a user interface standpoint, tests can still help guide QA teams by detecting major issues within the code that affect these areas. As the software is being written, automated tests can provide quick, visible feedback on any hangs, crashes and other exceptions that exist, eBay tester Julian Harty wrote for ACM Queue. Although manual operations may be able to detect some of these issues, it takes much longer and is not as consistent as automated testing.

"Test automation is imperfect and limited, yet it can be useful in catching various problems that would trip up some of your users," Harty wrote. "The work complements other forms of testing and helps inform the project team and usability experts of potential issues quickly, cost effectively, and reliably."

3) Regression Defects

How many times have you made changes to address one bug only to have another issue appear as a result in another area of your application? The problem is that this new bug is often undetected until the app is tested again, causing more work on the part of the QA team. By automating regression testing, you can test all module functionality every time an adjustment is made, reducing the cost, resources and time once needed to do such things manually, Software Testing Help stated. This type of functionality ensures that no new defects are missed, and that QA can have peace of mind that their software is up to expectations.

"[H]ow will you ensure that the new bug fixes have not introduced any new bug in previous working functionality? You need to test the previous functionality also," Software Testing Help stated. "Well you might do it manually but then you are not doing testing effectively. Effective in terms of company cost, resources, time etc. Here comes need of Automation."

4) The "Obvious" Bug

Automated testing can only do what it's been scripted to do, and is unable to think as a human tester might. For this reason, it's unlikely that automation would catch subtle issues. Software Testing Help gave the example of multiple automated scripts being run at once to log files. This led to data being overwritten and made it extremely difficult to conduct defect management due to the amount of database processes and scripts in action at once.

Rather than looking for nuanced defects, automated testing is excellent at finding issues that are more obvious. It can also quickly scan code for any immediate problems, whereas it could take a manual tester a significant amount of time to comb through the code.

Automation has a firm place in the testing environment as a tool to help QA quickly find issues. By understanding what types of defects automation is best at detecting, QA professionals can better leverage agile test management solutions for effective operations.