Defect Priority in Software Development: Prioritization Techniques

The concept of defect priority is the key to knowing which bugs to resolve first and which bugs can (safely) wait their turn. Defect priority is crucial for project management and product development because an unresolved defect could mean the difference between your software’s stability or a functionality nightmare. 

To ensure that your defect priority process can keep your software from affecting your technology, customers, and bottom line, you must know how to categorize defects, what factors impact defect priority, and the most efficient way to track and manage them. 

What is Defect Priority?

Defect priority is a critical concept in quality assurance, software development, and other fields where defects or issues need addressing. This concept refers to the relative importance or urgency assigned to a defect or issue based on various criteria, including customer impact, technical complexity, and frequency.

With defect priority, teams can more accurately determine the order in which defects should be addressed — enabling these teams to adopt a structured approach to managing and resolving problems. The primary goal of defect prioritization is to ensure that when required, limited resources are effectively and efficiently allocated to fix the most important or impactful issues first.

The Difference Between Defect Priority and Severity

For someone new to the quality assurance and software development field, defect priority and severity can easily be mistaken as the same concept. However the characteristics that differentiate them play a critical role in successful bug triage.

Defect priority determines the urgency of which bugs to fix — while defect severity measures the potential impact a bug could have on a product or software’s functionality. Defect severity levels are categorized as minor, moderate, major, and critical severity. Defect priority levels are categorized as deferred, low, medium, high, and critical priority.

Defining Defect Priority Levels

Defect priority levels are categorizations that indicate the relative importance or urgency of defects, typically ranging from critical (highest priority) to deferred (lowest priority), to guide their order of resolution in a project or product development.

Deferred defects are identified, but usually don’t produce enough of an impact to warrant immediate resolution. Low priority defects slightly impact software with only minimal issues. Teams often fix these defects at the end of a development cycle.

Medium priority defects impact software performance enough to be noticeable, but not enough to require immediate fixing. High priority defects are often found during bug triage and significantly impact software performance — potentially damaging the customer experience and the software itself.

The most severe defects are categorized as critical priority. Critical priority defects can result in security breaches, software failures, or anything that can bring your software functionality to a grinding halt. 

Factors Influencing Defect Priority

There are a variety of factors that determine a defect’s priority level. Factors like customer and business impact, technical complexity, frequency or repetition, dependencies, regulatory and compliance, and stakeholder input all affect where a bug is placed on the defect triage list.

• Customer and Business Impact: The priority of a defect is heavily influenced by the severity of its impact on a customer's user experience and the potential financial consequences it could pose to the organization. If a defect only impacts the way a webpage looks, it’s less urgent than fixing a defect that customers will encounter when purchasing a product. 

• Technical Complexity: Defect priority is affected by the technical intricacies and resource-intensive nature of the issue, as more complex defects may require significant time and effort to resolve. When a defect arises that will take a few days to fix, the process of fixing it should begin as early as possible to avoid further disruption. 

• Frequency or Repetition: The recurrence of defects can elevate their priority, especially if they affect a large user base — frequent occurrences that affect many customers may lead to widespread user dissatisfaction.

• Dependencies: Defects can rise in priority when they interrelate with other tasks or teams and act as roadblocks, necessitating their resolution to unblock progress across the entire project.

• Regulatory and Compliance Requirements: A defect’s priority is heightened if they can result in non-compliance with industry regulations or legal requirements, potentially leading to legal and reputational consequences.

• Stakeholder Input: In a software development project, stakeholders can include product managers, customers, business owners, and end-users. If a defect has varying impacts on these different stakeholders, their input is invaluable in determining its priority. 

For instance, if a product manager emphasizes the defect's alignment with the product's strategic goals, while customers emphasize its immediate impact on their user experience, stakeholder input can help balance these perspectives and assign an appropriate priority level.

Defect Priority Tools and Techniques

To support defect prioritization efforts, quality assurance, and software development teams can adopt a variety of tools and techniques — including the MoSCoW method and the Kano model.

The MoSCoW acronym stands for “Must have,” “Should have,” “Could have,” and “Will not have.” In the case of defect prioritization, the “must have” category will consist of the capabilities and features your software must be able to perform. Otherwise, the customer will not be able to use your software. While the MoSCoW method can help avoid any bias in the process of prioritization, there is no clear way to prioritize defects once they are placed in one of the categories. 

When measuring defect priority, the Kano model puts customer experience at the forefront of consideration. In the Kano model, customer needs are categorized as basic, performance, and attractive. If a defect impacts a basic need (like the checkout page functioning for an e-commerce platform), the defect would be classified as a critical or high priority. 

While the Kano model is effective in increasing customer satisfaction, it doesn’t consider the impacts a defect could have on the internal team and the technology itself. 

Seven Common Defect Priority Mistakes to Avoid

When assessing the priority of a defect, it can be easy to overlook certain considerations when you feel the pressure to fix every defect as fast as possible. To help prevent any defects from falling through the cracks, here are seven mistakes to keep in mind when prioritizing defects.

1. Ignoring Stakeholder Input: Neglecting input from customers, product owners, or end-users can lead to skewed defect priorities.

2. Relying Solely on Severity: Prioritizing defects solely based on severity may neglect their business or customer impact.

3. Overlooking Technical Complexity: Failing to consider the effort required to fix a defect can result in resource allocation issues.

4. Prioritizing Too Many Defects: Trying to address all defects at once can lead to inefficiency and project delays.

5. Neglecting Repetition: Ignoring frequent defects may lead to long-term user dissatisfaction and reduced engagement.

6. Ignoring Dependencies: Failing to address defects that block progress in other areas can disrupt the entire project.

7. Not Considering Regulatory Requirements: Neglecting compliance-related defects can lead to legal and reputational risks.

Take Your Defect Prioritization to the Next Level with AI

To successfully and accurately prioritize your defects, you’ll need a robust bug tracking and management process in place. How are you supposed to prioritize defects if you can’t track and manage them effectively in the first place?

When testing for and keeping track of bugs, developers, and engineers are bombarded with large volumes of data that can be challenging to digest. With Launchable’s Intelligent Test Failure Diagnostics platform, teams can transform the way they resolve defects to accelerate release time and increase product quality. 

The platform also provides users with intelligent bug triage and defect management features that:

• Automate bug identification.

• Quickly pinpoint new and frequent defects.

• Enable dynamic issue updates and insights.

• Provide more context for failed test sessions.

Better test failure triage leads to faster, more reliable software releases. Intelligently analyze and better understand test failures with Launchable.