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Why Bugs Exist in Software

Anthony Giorgio

Anthony Giorgio

04 October, 2017


In software and in nature, not all bugs are created equal. Thank goodness, (we’ve seen our fair share of both)! When we head out into the mountains for a weekend of camping with our families, we know that we should pack at least one canister of Off! Deep Woods. We also know that when we head back into the office on Monday morning, we need to arm our programmers with the bug protection they need.

(Hint: it doesn’t include Deet).

What is a software “bug”?

First off, let’s define what a bug is in software development. A bug is simply a flaw or failure in an application that renders incorrect or unwanted results. Basically, a bug is anything that causes the program in question to perform differently than how it should. While some software may be ridden with plague-like errors, others are functional, user-tested products that are serving their intended market but constantly be iterated upon to create the best UX. Many programming teams work on a release schedule to fix the known errors bogging their system down. Software has come a long way in the last 50 years! So you must be asking, “if we’ve gotten more affluent and created better systems for testing and mitigating defects, why does software still have bugs?” Good question. Keep reading to find out.

Why does software have bugs?


Software can be buggy for any number of reasons. Development and testing go hand in hand. When programmers finish writing code and documenting the obvious next step is testing. But testing every scenario takes time. Thankfully, some QA tasks can be automated. Some, however, like testing in different browsers or testing symbols in a text field are great places for bugs to crawl out of.  Also, note that the size of the software application affects the likelihood for defects to arise. More code written = more chances to make a mistake and more areas to test. Another factor in developing bug-free software is weighing the options between application robustness and getting a finished product out the door. Some bugs are liveable while others need to be squashed as quickly as possible.

Bugs love clients

While flexible requirements are ok, using the application as the specifications is not. The client should always be able to get what they want. That’s what they pay for! Sometimes, clients may request changes that they don’t understand the programming implications of. These changes can lead to inefficiencies that affect the whole development team. From rescheduling of engineers to new hardware requirements, dependencies can be counted on. Tracking the changes associated with a redesign adds complexity and in turn, errors. While this sounds a little scary, this is why developers use the Agile methodology.

Debugging with version control

Version control can present problems for any development team. It’s important that your programmers have a process for both documentation and versioning to avoid regression errors. While tools like GitHub and Subversion are among the biggest contenders on the market, errors may still creep into code if the team doesn’t use their version control system properly; taking care to make sure the most recent versions of each new module are linked when being tested.

Inexperienced programmers get eaten alive

The right team can make all the difference, and in software development experience is like a head net. If the programming team is writing sloppy code, the finished product will be sloppy too. If the code written doesn’t display an error where it should and also doesn’t serve it’s intended purpose, it’s going to be hard to find where the bug is hiding. For example, when programming in C++, an array value that is out of bounds can return any value that’s in its memory location. Most other languages would display an error in this circumstance. It takes some experience to learn how to protect code from errors like this.

Tricky little buggers

While perfectly functioning software is the goal for every programming team, it's highly unlikely that any code can be written without flaws. Some bugs may simply require the perfect set of circumstances that cause them to break, making them very difficult to detect. Here are a few examples of the right circumstances leading to the wrong outcome:

Date formats in the US and Europe are different (US, mm-dd-yyyy and EU, dd-mm-yyyy). If your software is intended for global use, it’s important to either program in several acceptable date formats, or list the format that you want the user to enter and display an error when the user input the info incorrectly. If a program does not have several acceptable formats, the user can enter a US formatted date that will work just fine until the 13th of the month!

If languages are mixed, incompatibilities may make the software malfunction. Apostrophes are a difficult character for some languages to process. A program can work as intended until someone puts in a last name like O’Malley.

While maintaining software updates is important, upgrades can be another story. Upgrades are often the culprit if software is displaying an error where it didn’t before. If a user’s account is suddenly performing incorrectly, it could be that a new database was not configured properly because of the software upgrade.

Keep bugs at bay by arming your development team with the tools they need to the best quality products possible. Experienced engineers with version control systems and a good understanding of Agile development are your keys to stopping creepy crawlers dead in their tracks. And please, don’t spray your computer with Deet...


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