Death by a Thousand Little Bugs

Software bug

Minor product defects that take only a few minutes to resolve are often never fixed; it seems there are always more important tasks to work on. If this sounds familiar, your test team may suffer from morale issues. And your product may suffer from “death by a thousand little bugs”. Fortunately, these problems can be fixed as easily as these bugs can.

Once testers get their hands on a feature, it doesn’t take long for low-priority defects to pile up in their bug-tracking database. These may include, for example, minor UI issues such as missing punctuation, inconsistent fonts, or grammar errors. These bugs tend to pile up because they are primarily cosmetic. Testers resolve the highest-priority bugs first–often rightly so. We should fix bugs that greatly affect functionality, performance, or security before fixing a spelling typo in the UI.

What can happen, however, is that we never fix many of these low-priority bugs. There are often more critical defects being discovered, so we continuously postpone the low-priority ones.

Unfortunately, some of the bugs left behind are those that were logged the earliest. There are few things I find more frustrating than reporting a simple bug that doesn’t get fixed. My typical complaint sounds something like this: “Why hasn’t this bug been fixed? I logged it weeks ago. It’s a one-line change that will take only two minutes to fix!”

A previous project I worked on provides a perfect example. Not long after I was given the first working build of the UI, I logged two minor bugs. One issue was logged because two buttons on the same page were not aligned properly. The other bug was simply that a sentence ended with an extra period. When the product was released more than four months later, the misaligned buttons and the extra period were still there.

Another problem is that even if these low-impact bugs don’t affect functionality, they can greatly affect the customer’s perception of the product. How can a customer fully trust a product, no matter how well it actually works, if there are mountains of minor defects? This is the “death by a thousand little bugs” syndrome.

Before I came to Microsoft, I ran an online store. One night I modified the shopping cart page, and the next day sales plummeted. When I reviewed the changes I had made, I realized that I misspelled two words and added a broken image link. I fixed these issues and sales quickly went back to normal.

The functionality of the page hadn’t changed at all. But potential customers saw the “minor” errors and assumed the entire shopping cart had poor quality. They certainly didn’t rationalize, “They must have spent all their effort making sure the functionality was solid. That’s why they postponed these obvious, but low-priority bugs.”

The “death by a thousand little bugs” syndrome exists because most teams evaluate each bug individually–and individually, each of these bugs is trivial; but in the aggregate, they are not. Collectively, they make users skeptical of your product.

The solution is that we shouldn’t always address high-priority bugs before low-priority bugs. But when do we make the exceptions? Here are three strategies that I think could help solve these problems.

  1. Set aside one day each month for developers to address the low-priority, low-hanging-fruit bugs. This is a great way to fix a lot of bugs in a short amount of time. It can also prevent your product from suffering from “death by a thousand little bugs.”
  2. Put aside one day every month to fix the defects that have been in the bug database the longest–regardless of priority. This helps prevent testers from becoming demoralized because bugs they logged months ago still haven’t been fixed.
  3. Once a month, increase the priority of all bugs that are least 30 days old. Developers can continue to pull bugs out of the queue in priority order, but the difference is that after one month, a bug that was logged as P4 (lowest priority) becomes a P3. After three months, it becomes a high-priority P1 bug. It may initially sound odd that low-priority defects, such as a misspelled word in a log file, will eventually be classified as highest priority. But doing so forces some action to be taken on the bug. As a P1, it now must either be fixed or closed by the Programmer Manager as “Won’t Fix”.

You may be thinking, “but I’m a tester, and these solutions have nothing to do with testers.” When I started in Test, that’s how I thought. I now realize that my primary responsibility is to make my product better, not just to log bugs. If these strategies would work well for your team, then you should lobby for them–they may even increase your own morale along the way.

Do you think any of these strategies work well for your team? What strategies have you tried in the past, and how have they worked? I’m very interested in hearing your comments.

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