5 Criteria to use for bug prioritization

Handling bugs is a big part of making software, especially when working on a large project. 

Unfortunately, when there are lots of bug reports to deal with, it’s easy to get swamped. 

Without a good plan for bug prioritization, your team might end up fixing small bugs while the ones that significantly affect the user experience or your business get left behind. 

That’s where this article comes in. 

We’ll guide you through five essential criteria to effectively prioritize bugs.

These criteria will help you identify which bugs need immediate attention and which can wait, ensuring your team tackles the most impactful issues first.

Let’s get started on making your bug-fixing smarter and more focused.

Let’s start with severity—one of the most crucial metrics in bug prioritization.

Severity is so commonly used to rank the order in which bugs are fixed, that some people confuse severity with priority.

We even made an article on the topic for a deeper understanding of their differences. 

For now, severity refers to the impact a bug has on the system’s functionality and the user’s experience. 

It’s about how much a bug can disrupt the normal operation of your app or how critical the affected feature is to the overall functionality.

There are standard categories for determining the severity of bugs, as you’ll see in the following image.

The ‘Lowest’ and ‘Low’ categories are less troublesome to categorize as they typically include bugs with minor visual issues or those that don’t significantly affect the app’s usage. 

However, the categorization of higher-severity bugs can vary based on specific circumstances. 

For instance, a bug that causes a slight inconvenience in a less critical feature might be categorized as ‘Medium’, but the same bug affecting a core functionality could be escalated to ‘High’ severity.

In general, however, you should consider a bug to be highly severe when it does some of the following things:

Security vulnerabilities should always be a primary concern. 

In today’s digital landscape, where data breaches and privacy concerns are rampant, securing user data is paramount.

According to data from iapp , most consumers worldwide are increasingly worried about online privacy.

A security flaw in your app not only risks user data but can also lead to legal issues and damage your reputation, so these should be considered high-severity and high-priority issues.

Other than security, consider the core functions of your app and carefully track any bugs that affect these functions.

Any bugs that either disrupt or break these core aspects should be considered a top priority.

To illustrate our point, consider a shopping app where the checkout process is vital.

Any bug in this process, like an error during the final payment process or even incorrect item listings, directly impacts the primary service of the app. 

Such bugs need immediate attention, as highlighted by the urgency in this Shopify user’s request for help with a bug causing items to disappear from their online store.

The fear of this user is completely justified.

Bugs that disrupt these carefully streamlined app flows can lead to significant revenue loss in a very short time and eventually erode user trust in the service.

Ultimately, users will start leaving in droves and find alternative apps that meet their needs.

That’s why treating issues related to important core functionalities as highly severe is essential.

Understanding and correctly categorizing bug severity is essential in prioritizing your development team’s efforts, ensuring they focus on the most impactful issues first.

But what if a severe bug occurred once, and then no other user reported it? 

What would you do in this case?

Common sense suggests you shouldn’t prioritize a bug that appears to be a one-off incident but keep a close eye on it for any future occurrences.

This approach is where the frequency of occurrence comes into play, where we focus on how often a bug is reported or encountered.

One key metric to consider while analyzing bug frequency is the number of bug reports for the same bugs. Take a look at an example frequency table below.

In the table, bugs are ranked by the number of reports. Naturally, bugs reported more frequently should be prioritized because they affect more users. 

But, you don’t have to wait for users to start experiencing problems with an app and for reports to start piling up before focusing on frequently occurring bugs.

You can use statistics like the one shown below to concentrate on bugs that occur most frequently across all apps.

By doing this, your team can pay special attention to these types of bugs.

This proactive approach helps in catching and fixing potential widespread issues before they become major problems for your users.

But there’s another method to consider as well—making logical assumptions. 

What do we mean?

Let’s say your team received the bug report shown below from the testing team after a major app update.

Because this bug affects the login screen functionality—a feature that everyone uses it’s logical to assume it will impact a significant portion of your user base. Such a bug should be addressed immediately.

Contrast this with a bug found in a less frequented area of your app, like an issue within the settings section that only appears under certain conditions.

In this case, the bug might not be a high priority because it’s unlikely to affect a large number of users.

Overall, considering the frequency of a bug’s occurrence is a practical approach to prioritizing issues within your app.

By focusing on the most commonly reported or likely bugs, you can efficiently allocate your resources to address the most pressing issues first.

Even if a bug appears frequently, it’s not the only determinant of whether it needs to be a priority.

Ultimately, satisfying your users is what matters most, so measuring the impact a bug has on them is a top priority.

Take a look at the following image showing two bug examples.

From these examples, a bug that disrupts a key app feature will take priority over a minor visual glitch.

The reason is simple: the former has a more significant negative impact on the user experience.

In real-life scenarios, you can gauge the impact of particular bugs by what users say in online reviews of your app. If there’s a lot of negative sentiment about a specific issue, it’s a strong indicator that the bug should be prioritized.

Impact is such a valuable metric for prioritizing bugs that some scoring systems, like the RICE score shown below, incorporate it.

The RICE score, useful for both feature and bug fix prioritization , considers the reach, impact, and your confidence in these two factors, and then weighs them against the effort needed for implementation.

The team at Intercom that developed RICE categorized impact as follows: 

You can create your own impact categories based on your app’s specific context and user base.

Another important consideration is which users are affected by a particular bug. 

Look at the image below showing common app user categories.

A bug might impact all these user groups, or it might primarily affect a specific segment, like paying customers or power users.

Prioritizing bugs that affect these key user groups can ensure continued revenue and maintain your app’s reputation as a reliable and user-focused product.

In contrast, you might choose not to focus on bugs that affect occasional users or bugs that occur to a small percentage of regular users, even if the impact is high.

By focusing on the bugs that most negatively affect your users, especially those in key user groups, you can ensure a better overall experience and maintain user satisfaction and loyalty.

Bug reproducibility refers to how consistently a bug can be triggered or observed.

It’s about whether developers can easily recreate the bug following specific steps. 

A reproducible bug allows developers to quickly identify the root cause and work towards a solution.

On the other hand, a non-reproducible bug presents a significant challenge.

These bugs require more effort to fix as developers have to work with limited information, often relying on vague descriptions or sporadic occurrences.

What’s worse, some bugs have dependencies, meaning they can only be resolved when other related issues are addressed first.

Consider the following example.

Imagine a bug that prevents users from completing their checkout process. At first glance, it might seem like a straightforward fix. 

However, the root cause could be a deeper issue, such as a gateway connection error. Without understanding and addressing this underlying problem, the checkout bug remains unsolvable.

This is where our tool, Shake , comes into play. 

Shake helps users create detailed bug and crash reports, providing developers with all the information they need to efficiently tackle bugs and uncover their root causes.

By simply shaking their device, users are taken to a new ticket screen where they can describe the bug and provide additional information.

However, sometimes even this detailed info isn’t enough.

That’s why Shake goes a step further, automatically attaching over 70 different metrics of useful data to each report.

This data includes automatic screenshots and video recordings, which can be crucial in understanding the context and environment in which the bug occurs.

Such comprehensive data collection aids in tackling even the most elusive bugs.

All in all, the reproducibility of a bug is a key factor in determining its prioritization. 

Easily reproducible bugs can be addressed swiftly, while those that are harder to replicate may require more resources and time, and using tools like Shake can prove invaluable in this process.

Other than focusing on your users, you should also consider the business impact of bugs.

Why is this important?

Because bugs can affect not just the user experience but also your app’s bottom line.

You need to look at how key features that support your business offerings are impacted by bugs.

Let’s take Uber’s app as an example.

For a service primarily offering transportation, features like location tracking, ride booking, and payment processing need to work flawlessly. 

A bug in any of these areas can disrupt the core service, leading to lost revenue and dissatisfied customers.

But it’s not just about core features. Other business metrics, like the ones illustrated next, are crucial as well.

Consider a minor bug that, while not affecting the app’s functionality significantly, impacts customer acquisition or retention.

Such a bug should be a priority because maintaining a consistent user base and revenue stream is vital for your business’s survival.

For instance, look at this Reddit thread discussing a bug in a mobile game.

The bug caused users’ save data to be overwritten, erasing hours of gameplay.

This type of bug can severely impact the user experience, leading to frustration and potentially causing users to abandon the app altogether.

If that was a paying user, that’s a direct hit on the revenue. 

Moreover, bugs like these can damage your brand’s reputation.

In today’s connected world, a single significant bug can lead to widespread negative publicity, affecting user trust and your app’s market position. 

By focusing on bugs that affect key business metrics and core functionalities, you can ensure that your app not only provides a great user experience but also supports your business’s overall health and growth.

And there we have it, our deep dive into bug prioritization is complete. 

We’ve looked at different ways to think about bugs including how severe and frequent they are, how they affect your users, and what they mean for your business.

Our aim was for you to understand why and how to use these criteria effectively. 

By applying them, you can prioritize bugs in a way that makes the most sense for your users and your project.

It’s all about combining these insights to make informed decisions, leading to a smoother development process and a better end product. 

Go on and squash those bugs in the smartest way possible!