Bug severity and priority are closely linked concepts, each addressing distinct aspects of a defect. While related, these terms hold subtle differences, and it is crucial for all stakeholders in the development process to discern between them. This distinction facilitates determining the optimal course of action when faced with the question "What should be addressed first?"—a query that often sparks discussions among QA engineers, developers, and stakeholders. This article aims to provide clarity on the fundamentals and alleviate tensions in decision-making.
What Is Bug Severity?
Bug severity refers to the degree of impact a specific defect imposes on the software. The more significant the effect of this defect on overall functionality or performance, the higher the severity level assigned.
LEVELS OF BUG SEVERITY
Blocker (S1): This means a bug that completely stops the software from working, like a shutdown.
Critical (S2): It's a significant issue in crucial parts of the software, affecting key features.
Major (S3): This is a bug that has a notable impact on the application, but other parts still work.
Minor (S4): It's a problem that might be confusing but doesn't hugely impact how users experience the software. Often seen in UI (user interface) bugs.
Low/Trivial (S5): This is a minor bug that doesn't really affect how the software works. It could be something like a small spelling mistake.
What Is Bug Priority?
Bug priority helps decide the order in which to fix defects. If a bug has higher priority, the development team will address it sooner. Usually, priority is linked to severity, meaning more critical issues like blockers get fixed before minor ones.
DIFFERENT LEVELS
High (P1): This bug is crucial and needs a quick fix.
Medium (P2): The issue is important but can wait for a regular fix, like in the next sprint.
Low (P3): The bug is not a big deal and can be fixed later or might not be fixed at all.
Based on release timings, we can categorize bug fixes into three types:
Hotfix: Critical issues that significantly impact users and business performance. These need immediate attention, such as fixing installation failures or login issues.
Upcoming Release: Issues that are problematic but don't affect the core functionality. Examples include broken layouts that are confusing but don't interfere with actual tasks. These fixes can be included in the tasks planned for the next update.
Later Sprints: Non-severe problems with no immediate pressure from users or the business. These bugs go into a backlog and are resolved at some point during upcoming sprints. This is common for dealing with typos and minor compatibility issues.
Do We Need Both Severity and Priority?
Yes, both severity and priority are important in managing defects, but they serve different purposes.
Severity indicates how much a defect impacts the user. QA specialists assess this based on the user's perspective, determining how badly the system is affected.
Priority determines the order in which developers fix bugs. This decision is made by individuals like the Product Owner or Project Manager, considering various factors, including severity. However, severity doesn't always dictate priority. Stakeholders must weigh business implications, and these terms are managed by different groups in software development.
HOW TO DETERMINE BUG SEVERITY?
To figure out how severe a bug is, QA engineers look at how often it happens and how much it affects the functionality. Both of these aspects are important. For example, if there's an issue with the size of icons on all product pages and another problem with buttons overlapping on two popular products, both are layout problems. However, the first one just looks bad, while the second one stops people from being able to make a purchase. They're similar issues, but their severity levels are different.
HOW TO DECIDE BUG PRIORITY?
If you're unsure about setting bug priority or if you're a bit frustrated with how bugs are being prioritized, here are some questions to help you understand the process better:
How many users are impacted by the bug?
Which software area is affected?
Which Devices, platform, O.S are affected?
Does the company experience financial or users losses as a result?
Are there legal or security implications associated with this software problem?
As you can see, it's not just about how severe the bug is. It's crucial to pay attention to business-related factors as well.
DIFFERENT SEVERITY AND PRIORITY SCENARIOS
Let's explore different combinations of severity and priority to understand why both are important:
High severity with high priority: A user can't log in. No need for a lengthy explanation; it's a critical issue.
Low severity with low priority: The design of a rarely visited section doesn't match the updated website design. This can wait for updates, especially if it's not affecting many users.
Low severity with high priority: There's a broken layout or typos on top-visited pages. While it doesn't impact functionality, it affects how users perceive the brand, satisfaction rates, and even revenue.
High severity with low priority: The layout doesn't fully load in older versions of legacy browsers. Although it affects the entire application, fixing it may not be urgent if only a few users access the website via these browsers.
Manage Conflicts
Confusion and conflicts can arise when there's a mismatch in expectations between the development team and stakeholders regarding bug severity and priority. Sometimes, both parties may think they have valid reasons for suggesting different priorities. However, the final decision rests with stakeholders.
If a QA engineer or developer disagrees with the assigned priority, they should calmly raise the issue and seek clarification from the decision-maker. Similarly, if stakeholders are unsure about the assigned severity, they should ask for explanations.
Conflicts often stem from human factors, and when everyone is passionate about delivering the best product, miscommunications can happen. Transparent communication is key to avoiding such situations. Each team member should be aware of the development process hierarchy and use good judgment in seeking clarifications when needed.
In Conclusion
Severity and priority are managed by different teams, but severity plays a crucial role in prioritizing defects. The project leader is responsible for considering both factors and making decisions. It's important to distinguish between bug severity and priority, and to use these terms accurately. Team members should understand their roles and responsibilities, with QA engineers supporting development with product quality expertise, while analysts and managers ensure decisions align with business goals and the overall project vision.