8 bug prioritization methods to try

Navigating the maze of bug prioritization is crucial for any software development team. 

But that doesn’t make it any less difficult.

We understand the challenges you face—the overwhelming influx of bug reports, the pressure to maintain quality, and the need to deliver on time. 

To handle these issues, you might want to optimize your bug prioritization process but don’t know where to start.

This article is here to offer some help. 

We’ll explore eight effective methods to streamline your bug prioritization process, each method offering a unique approach to tackling the bug backlog, ensuring your team can focus on what truly matters. 

Ready to dive in?

The MoSCoW method is a straightforward yet effective approach to prioritization. 

At its core, this method involves categorizing tasks or items into four distinct groups to determine their level of importance. Each of these groups represents a different priority level, illustrated next.

As you can see, the Must-have category has the highest priority, followed by Should-have and Could-have, while Won’t-have are optional issues to address and are typically left on the backlog.

In the above example, we used MoSCoW to categorize bugs based on their impact on an application.

However, it’s important to understand that this method doesn’t give you the criteria or rules for bug prioritization. It’s just a very useful way to organize things. 

Therefore, your team will need to consider various factors to determine which category each bug belongs to like the following:

Another thing to consider is the resources and effort you are planning to allocate for each of the four categories.

Agile Business suggests aiming for no more than 60% of effort to Must-have bugs, ensuring these critical issues are confidently addressed. The other 40% is then allocated to the other 3 categories, typically 20% for both Should-have and Could-have.

Overall, the MoSCoW method offers a flexible yet structured way to prioritize tasks.

Now let’s turn to RICE scoring—a methodical approach to prioritizing tasks, particularly useful in product management and bug fixing.

This method evaluates tasks based on four key factors: Reach, Impact, Confidence, and Effort. 

For bug prioritization, you would simply take each bug on the backlog, and by assigning scores for the four factors, teams can calculate a RICE score to determine the priority of each task.

Consider a bug that needs prioritization. Its RICE elements might be defined as follows:

Calculating the RICE score for this bug, we get: (300 * 3 * 0.7) / 3, which is a score of 210.

After calculating scores for other bugs, you can compare them to prioritize effectively. You can use a table like the one shown below.

Clearly, the bug in our example won’t be a priority as there are bugs with higher RICE scores on the backlog, with the most pressing one being Bug #101.

As you can see, RICE scoring offers a quantitative and objective way to prioritize tasks, ensuring that resources are focused on the most impactful and feasible tasks first.

The Kano Model offers a unique perspective on prioritization, especially in the context of bug fixing and feature development. 

This model categorizes product features and bugs, based on two dimensions. These are customer satisfaction and the degree to which expectations are met. 

Based on these dimensions, features are classified into three main categories: Threshold, Performance, and Excitement.

Threshold features are ones that customers expect as a minimum in a product. Their absence leads to dissatisfaction, but their presence doesn’t necessarily increase satisfaction. 

Performance features, on the other hand, improve customer satisfaction linearly—the better these features perform, the happier the customers are. Finally, the Excitement category has features that exceed customer expectations.

Consequently, any bug affecting each of these features will negatively affect the corresponding aspect of the customer experience. 

Take a look at the next table, depicting some bugs that can affect the three categories of features.

Prioritizing bugs affecting threshold features is crucial for the app to function properly while fixing ones affecting the performance category can significantly enhance user experience.

These are basic priorities that need to be handled before anything else.

On the other hand, excitement features, though not essential, can create a strong positive impact and should be considered for long-term user satisfaction and retention.

So, the Kano Model helps in understanding the impact of bugs on customer satisfaction and can guide teams in prioritizing bug fixes that align with user expectations and satisfaction levels.

Severity and priority ratings are a commonly used method in bug prioritization, offering a clear framework for assessing and addressing software issues. 

As the name suggests, this method evaluates bugs by determining their severity and priority levels.

Severity refers to the impact a bug has on the system. A critically severe bug might cause system crashes or data loss, while a low-severity bug might only have minor, cosmetic effects. 

Priority, on the other hand, determines how quickly a bug needs to be addressed. A high-priority bug might not be severe but requires immediate attention due to its user impact, whereas a low-priority bug can be deferred.

This method of ranking bugs involves assessing both their severity and priority, as shown in the next graph.

You might wonder why not use severity alone for prioritization. The reason lies in the different impacts bugs can have. 

For instance, a high-priority but low-severity bug might be a minor cosmetic issue that still affects a key customer or a critical business process, necessitating immediate attention.

The severity and priority ratings method provides a balanced approach to bug prioritization, enabling teams to address the most pressing issues effectively while managing the overall bug backlog.

Next up we have Weighted Shortest Job First (WSJF), a prioritization technique widely adopted in Agile frameworks. 

It’s designed to optimize the flow of value by prioritizing tasks that offer the highest value with the least effort.

WSJF works by calculating the Cost of Delay for each bug, which is usually calculated as the combination of business or user value, time criticality, and risk reduction or opportunity enablement. 

Then, the job size or effort required to complete the task is determined and the WSJF score is calculated using the formula shown below.

Bugs are then prioritized based on their WSJF scores, with higher scores indicating higher priority.

To illustrate how this scoring method is used, consider the next two bugs and their corresponding WSJF elements in the image below.

When it comes to scoring each of the four components of the formula, you can use your organization’s method of calculating value, criticality, risk, and job size, but many suggest using the Fibonacci sequence (1,2,3,5,8,13,21) for simplified categorization.

What you end up with are different WSJF scores with which you can easily sort bugs more objectively.

Overall, WSJF is a powerful tool for Agile teams, helping to ensure that efforts are focused on tasks that deliver the most value in the shortest time.

Our sixth method is Risk-based testing, a strategic approach to both software testing and bug prioritization.

This method involves assessing the potential risks associated with software bugs and prioritizing testing efforts based on this assessment.

Each bug is evaluated for its severity or the impact it has if it occurs and its probability—the likelihood of the bug occurring. 

These two factors are taken into consideration together, usually by constructing a risk assessment matrix as shown below.

The matrix uses a combination of severity and probability levels to categorize bugs. 

The one above has four severity levels and six probability levels that tell us whether the bug will definitely and frequently occur or whether this possibility is remote or completely eliminated.

With this method, a high-priority or high-risk bug could be one that causes the application to crash during peak usage times and which is categorized as Probable or Frequent, while a low-priority bug might be an occasional, minor glitch in a less critical part of the application.

As you can see, the risk-based testing approach allows teams to focus their efforts on the most impactful issues, ensuring that the most critical bugs are addressed first and reducing the overall risk to the project.

The value vs. effort matrix is a practical tool for prioritizing bugs based on their perceived value and the resources required to fix them. 

You can take a look at the matrix in the following image.

In this matrix, bugs are plotted based on the two dimensions and divided into four quadrants.

These quadrants are: 

Here are some example bugs that can be placed in each quadrant:

Naturally, bugs in the Do It First quadrant are prioritized as they offer great business or user value for relatively little effort.

Major Project bugs are looked at as well, while Fill-Ins can be addressed if there are spare resources. Thankless Tasks are either avoided or the lowest priority.

A useful method to keep in mind, this matrix is extremely versatile and can help teams make informed decisions about which bugs to prioritize.

Finally, we’ll talk about a bug prioritization method that takes into account the overall project and resources.

Critical Path Analysis (CPA) is a method that focuses on the impact of tasks, including bugs, on the project timeline. It’s particularly useful in project management for identifying the sequence of crucial tasks that determine the project’s duration.

CPA involves mapping out all the tasks required to complete a project, including their durations and dependencies. An example can be seen below.

The critical path is the longest sequence of tasks that must be completed on time for the project to be finished by its deadline. Any delays in tasks on this path will directly impact the project’s completion date.

For example, a bug can affect a task on the critical path in the example we provided above, such as “Task D” in the sequence from Start → Task C → D → E → Finish, so it becomes a priority to fix. 

This is because resolving this bug is essential to prevent delays in the subsequent tasks and, ultimately, the project’s completion within deadlines.

As you can see, CPA is a great method for bug prioritization in relation to project management, providing a clear framework for identifying and addressing issues that affect efficient project delivery.

And that’s a wrap! We’ve covered eight distinct bug prioritization methods, each with the potential to revolutionize your team’s approach to bug management. 

From traditional techniques to some innovative strategies, these approaches cater to a variety of needs and workflows. 

We hope that you’ve discovered at least one method that resonates with your team’s unique challenges, or you’ve stumbled upon a few techniques you hadn’t considered before. 

Implementing these methods can lead to a more streamlined, effective bug prioritization process, ultimately enhancing your product’s quality and your team’s productivity. 

So go ahead, experiment with these strategies, and find the perfect fit for your team.