What is Defect/Bug Life Cycle in Software Testing

OVERVIEW

The bug life cycle comprises different phases that a bug generally undergoes from the time it is identified and fixed. It includes several processes and steps that allow software developers and testers to identify, report, resolve, and verify the bugs.

In the process of software development, bugs or defects commonly interfere with the software application's functionality and performance. A bug is a consequence or error that occurs due to a fault in the program's coding. In the book Code Complete, Steve McConnell stated in the chapter Developer Testing that the software industry experiences about 1-25 errors per 1000 lines of code. Further, IBM stated that the cost of fixing the identified bugs in the testing phase could be 15x more than the cost of fixing those in the later stage of development.

The above statistic highlights the need to adopt a structured approach to handle and manage the bugs. However, if not managed effectively, it could lead to a loss of revenue and profit for the organization as users can stop using applications with bugs and defects.

It is highlighted in Statista that 1.7 million users abandoned apps due to the presence of bugs. Thus, ensuring the bug fixes in the Software Development Life Cycle is very important, and here comes the bug life cycle.

By following a well-defined bug life cycle, development teams can streamline their bug-fixing efforts, reduce the chances of reoccurrence, and deliver high-quality software applications to end-users.

What is a Defect or Bug?

A software bug is an unforeseen issue in software or hardware, often arising from external interference not anticipated by the developer. These glitches can range from minor inconveniences like frozen screens to unexplained error messages, impacting the program's performance. Understand the bug life cycle to effectively manage and resolve these issues.

Regarding a bug, it might appear that defect and bug are synonyms. However, they are different in meaning. The bug is understood as the unexpected behavior in the software application while it is being tested. It generally leads to malfunction, which might occur due to coding errors, miscommunication between the team, complexity of code, and poor understanding of the requirements and others.

However, defects or bugs can occur due to the mistakes developers make while designing or developing software applications. Testers must comprehensively test the software applications to detect bugs and flaws. For this, they should understand the bug life cycle before heading towards the workflow and distinct states of defects.

• Defects can occur at any stage of the Software Development Life Cycle.
• Detecting and removing defects early reduces the overall cost of quality.
• Removing defects in the same phase they were introduced minimizes the cost of quality.
• Static testing identifies defects without involving debugging, leading to cost savings.
• Dynamic testing uncovers defects when they cause failures.

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What is a Bug Life Cycle?

The bug life cycle or defect life cycle in testing is a process that involves different stages through which a defect progresses during its lifetime. It starts when a tester identifies a new defect while testing the application. The cycle continues until the tester finds a resolution and closes the bug to prevent its recurrence.

It is common for testers to encounter errors or issues within a software application which can be highly detrimental in the production environment. For example, in 1991, in a bug in the MIM-104 missile system, 28 American soldiers died as the bugs caused the system clock to drift by 1/3rd of a second. It has led to failure in the interception of the other missile.

Every software organization works with the motive to develop an application bug-free to ensure its quality and meet end-user requirements. To this, in most organizations, the bugs are fixed before the release of the software application. This fix is only achieved by following a systematic defect life cycle.

The defect life cycle varies from organization to organization and project to project because it is the development procedure, platforms, testing methods, and testing tools that differ depending on the organization and projects. It ensures that bugs are tracked, prioritized, and resolved logically and organized, preventing them from slipping through the cracks and causing further issues.

The main purpose of the defect life cycle is to coordinate and communicate the present status of defects seamlessly. It provides a structured framework that allows for the smooth transfer of the defect between different assignees, ensuring a systematic and efficient defect-fixing process.

Advantages of Bug Life Cycle

The bug life cycle provides several benefits that help improve the overall software quality and efficiency of software development:

• Software development teams can systematically identify, document, and resolve bugs and defects by following a structured bug life cycle. This process ensures that the final software application is high quality and can be relied upon by users.
• Each step in the bug life cycle is marked and documented, making tracking and managing bugs easier. This systematic approach reduces the resources needed to find and fix problems, resulting in cost savings during development. Besides, catching bugs early prevents more extensive rework or expensive fixes later on.
• The bug life cycle promotes better communication among team members involved in development and testing. Each bug progresses through different stages, and its status is effectively communicated to the relevant individuals. It fosters better understanding and empathy, ensuring everyone knows the software's state and progress in resolving bugs.
• The bug life cycle allows for the early identification of issues and defects. It enables developers and testers to catch bugs before they escalate into bigger problems. Detecting issues early reduces the overall cost of finding and fixing bugs, as it is easier and less time-consuming to address issues in their early stages.
• By effectively managing bugs and following a systematic bug life cycle, software development teams can deliver better services to their customers. Their software applications are more reliable, stable, and free from major defects. It leads to higher customer satisfaction as users can trust and depend on the software application.

Participants of a Bug Life Cycle

You may think different teams might be involved in this process. Yes, it is true, but the software developers and testers are the two main participants in the bug life cycle. Let us learn about their role so that you may understand their responsibility in the progress of the bug life cycle.

The tester is responsible for identifying and documenting the bug in the software application. However, the developers are mainly into the task of fixing it. When you work in a large team, other specialized individuals are involved in defect management. On identifying the severity and priority of the bug, the testers, a different group of individuals called the triaging defect committee, come into action.

The bug triaging committee evaluates and prioritizes the defects, engaging in discussions with team members to understand the specifics of each issue. The triaging defect committee typically consists of a Test Lead or QA Engineer who assesses bug severity, a Development Team Lead who evaluates potential risks, a Project Manager who decides bug priority and discusses deadlines for fixing, and a Development Team Lead who assigns the task to a developer and sets deadlines.

Depending on the organization's size, higher-level personnel such as Department Heads and the Chief Technology Officer (CTO) may also participate in these discussions to provide insights. The exact workflow can vary based on the team structure and established processes.

States of Defect

In the defect life cycle, the defects undergo three crucial states that define their progress during the software development or issue resolution process. Such states mainly vary depending on the specific methodology or use of workflow. Let us understand those from below-given information:

• Initial state: The initial state signifies the starting point of a defect or issue within a software development or issue resolution process. It represents the condition of the defect when it is initially detected or reported. Essentially, these states mark the commencement of the defect resolution process, involving gathering information or registering defects as open or new.
• Returned state: The returned state denotes the phase to which a defect progresses once it is evaluated or reviewed. These states indicate that following the defect assessment, it may either be rejected for various reasons or necessitate further information or clarification before any additional steps can be taken.
• Confirmation state: The confirmation state refers to the ultimate state of a defect after its resolution and validation. These states indicate that once the defect has been rectified, it must be tested and closed or marked as resolved after successful verification.

Now that you have understood the three main states of defect, it is equally important to walk through each of the different stages within those that a defect undergoes in the defect life cycle workflow or bug life cycle.

Stages of Bug Life Cycle

The stages of the bug life cycle represent the particular state of bugs in their life cycle. The defect life cycle workflow is not fixed as it varies from team to team, organization to organization, and project to project. Some organizations use Jira, and some may use Backlog to follow the defect life cycle workflow. Let us take a closer look at each stage of the bug life cycle.

New

It is the first state of bug where the tester detects the bugs for the first time during software testing. The tester creates detailed specification documents on bugs, like what it is, the way to reproduce them, and what are the tests due to which they failed. Following this, testers assigned those bugs as “New” bugs. This document is provided to the development team so it can be referred for early fixes.

Assigned

The bugs marked as “New” will be approved and assigned to the corresponding development team or team by the project or other responsible person. It is done so that the team can start working on the bug fixes. When it is assigned to the team, the status of bugs changes to the “Assigned” state.

Open

In this stage of the bug life cycle, the software developers evaluate and analyze the bug based on the reports developed by the testers in the first stage. Following this, the developer initiates the process of bug fixing and reimplementing the portion of code which caused the issue in the functionality of the software application.

In this stage, the developer may encounter a situation where they may feel that the bug is inappropriate. In this situation, the bug is marked to different states in the defect life cycle workflow, like Duplicate, Rejected, and Deferred.

Fixed

In this stage of the bug life cycle, the developers fix the new and open bugs after completing all the related software tests and validation. Here, required code changes are done to fix the bug. When fixes are done, developers forward them to the testing team.

Pending Retest

In this stage of the bug life cycle, the bug is assigned as “pending-retest,” which is the time interval between the bug fixing and retesting of bugs to check whether the issue has been resolved. For this, the developer team gives new code to the testing team for performing a retest of the software application. When the code or application is pending to be retested from the tester side, the bugs are assigned to the pending-retest state.

Retest

In this state of the bug life cycle, the actual retesting of the software applications occurs. Here they test whether the bug found in the software application has been fixed or not based on the requirement mentioned in the first stage of the defect life cycle workflow. They also check that the process of fixing a new bug has not impacted any existing functionality, which could introduce new bugs.

Reopened

During the retesting process, if the tester discovers that the bug is not completely resolved or if a new bug has popped up, they change the bug's status to "Reopen." It requires assigning the bug back to a developer for further resolution. Once again, the bug goes to the “Open” state and continues with the defect life cycle workflow. In other words, the bug has to go for re-fixing by the developer team.

Verified

If, during the retest stage, the tester determines that all issues have been resolved, they assign the bug the "Verified" state in the defect life cycle.

Closed

It is the final stage of the bug life cycle after ensuring the bug has been fixed. The bug's status is changed to "Closed" once it is confirmed that it no longer exists.

There are a few miscellaneous states that may occur after the "Open" stage in the bug's life cycle:

Rejected

If the developer believes that the bug report created by the tester is incorrect or not genuine, they may reject the bug, placing it in the "Rejected" state.

Duplicate

Suppose the developer determines that the bug is a duplicate of another "Open" bug or can be resolved by fixing another existing bug. In that case, they may assign the bug to the "Duplicate" state.

Deferred

This state may be used when the software developer determines that the bug is not crucial to fix at the current time, the cost of fixing the bug is high, or it is not possible to fix it immediately. The developer places the bug in the "Deferred" state to be addressed in a future software release.

Not a Bug

When the developer concludes that the bug has minimal impact on the proper functioning of the software, they assign the "Not a Bug" state to the bug in the defect life cycle.

Non-reproducible

In the defect life cycle, if the defects cannot be reproduced for reasons like platform mismatch, data mismatch, build mismatch, and others, the developers mark the state of a bug as “non-reproducible.”

Can’t be fixed

In some situations in the bug life cycle, the developers may not fix the bug. This actually occurs due to issues like lack of technology support, high cost of fixing bugs, lack of required skill, and others. In such a state, the bug is assigned to be “Can’t be fixed.”

Need more information

This state of the bug life cycle is similar to the “non-reproducible” state. However, it is quite different from it. In cases when the developer cannot reproduce defects due to the lack of sufficient information on the steps or documents provided by the tester or due to ambiguous defect documents, the developer changes the status of a bug to “Need More Information.” When they receive good defect documents from the testing team, the developers fix the defects.

Example of a Bug Life Cycle

In the above section, we have discussed the various states and stages of the bug life cycle. Let us understand this with an example that will clarify your whole concept of defect life cycle workflow to have a clear view of this.

Scenario: Consider you are going to test an online bookstore with multiple books to be added to the cart.

• New: The QA engineer encounters a problem while testing the online bookstore website. He adds a book to the cart, but the quantity cannot be changed. The QA engineer logs the bug as "New."
• Assigned: The project manager reviews the bug and assigns it to the back-end developer responsible for the cart functionality.
• Open: The back-end developer receives the bug and attempts to reproduce it based on the provided instructions. He confirms that the "+" button does not work as intended. The bug status is changed to "Open," and the back-end developer starts identifying the root cause.
• Duplicate: In some cases, the back-end developer may identify that another tester has already reported the bug. In such instances, the back-end developer marks the bug as "Duplicate" without further action.
• Rejected: The back-end developer follows the bug report instructions and successfully adds the book to the cart, finding no issues with the quantity change. Possible reasons for the problem could include an unstable internet connection or missing information in the bug description. The back-end developer rejects the bug if it is deemed invalid.
• Deferred: The back-end developer determines that the bug only occurs on the Firefox browser, which has a small user share. He decides to address it later, prioritizing a more critical issue regarding payment failures.
• Not a bug: Upon further identification, the back-end developer realizes that the QA engineer's attempt to purchase an additional eBook is not a bug. The website's logic allows users to access eBooks from any device without needing multiple purchases.
• Need more info: The back-end developer requires additional information to fully understand the bug's conditions. He needs to know if the user is logged in and if the QA engineer encountered the issue while adding an item on a product page or during order confirmation.
• Cannot be fixed: The back-end developer is aware of a bug that resists resolution despite multiple attempts. Fixing it would involve a thorough codebase review, which is not feasible at the moment. Users can manually input the number "2" to order multiple books as a temporary solution.
• Fixed: The back-end developer locates and corrects the flaws in the code, resolving the bug. The status changes to "Fixed."
• Retest: The QA engineer receives a notification about the status change and retests the functionality. He ensures that users can now change the number of books in the cart using the "+" button. The bug is set to "Retest."
• Reopened: Unfortunately, during retesting, the QA engineer discovered that the bug still exists. Clicking on the "+" button fails to change the quantity. The bug is reopened and assigned back to the back-end developer for further fixing. It will go through the Fixed and Retest stages again.
• Verified: During retesting, the QA engineer confirms that the button now works as expected, allowing users to adjust the number of items in the cart using the "+." He changed the defect status to "Verified."
• Closed: Seeing that the bug has been resolved, the project manager closes the bug as the final step in the bug life cycle.

How to Report and Track a Bug?

The reporting and tracking of the bugs depend on the tool used. When you use any professional bug tracking or reporting tools, it will be able to record, monitor and report bugs during the software testing of the application. Such tools ensure that all the bugs are detected and fixed before the release of the software applications in the market.

Some organizations use integration with Slack, Jira, GitHub, and Trello to create a robust testing ecosystem. With such integration, you can improve the result of the bug-tracking life cycle. However, a few aspects should ensure reporting and tracking of the bugs.

For example, the team must assign the identified bug to the appropriate member for fixing and focus on the priority bug first. Also, maintenance of regular updates on the status of the bug needs to be followed by the team so that each member is involved in the bug’s current state and prevents duplicated efforts.

Tools for Detecting and Reporting Bugs

Several tools are available in the market to identify and track the bug and ensure it is fixed throughout the Software Development Life Cycle. Following are some handpicked lists of top bug-tracking tools which can be used.

• Jira: It is one of the most used bug-tracking tools because of its easy-to-use framework. It allows the team to capture and organize the defect detected in the software application and prioritize the defect by updating them with the software project. The best part of Jira is its seamless integration with the code development environment, making it a perfect fit for developers.
• Bugzilla: It is also among the popular bug-tracking tools that are open source and have amazing features. For example, Bugzilla can send email notifications when there is a change in the code, which helps the developers easily track the progress and status of bug fixes. The team can easily analyze the large data and identify an area that needs fixes through its provided reports and charts. It can also take screenshots and videos, which help to document and reproduce bugs.
• Zoho BugTracker: It is a defect-tracking tool that helps testers and developers to create custom fields and workflows with its friendly user interface to detect any software bug. It gives a detailed report on the number of bugs found and resolved, along with other appropriate metrics. The team can add comments to the bug reports so everyone involved remains informed and collaborates.
• BugHerd: BugHerd provided the easiest option for tracking bugs and managing website feedback. It can pinpoint bugs and give feedback directly to particular elements on a website. This helps the team to locate the exact location of the issues and ensure their timely fixes. BugHerd also provides technical information on the bug, which helps in giving valuable details for troubleshooting.

How to Write a Good Bug Report?

While performing software testing, when you detect any bug in the software application, it is important to create a bug report. The bug report is defined as documents having clear descriptions of the bug in detail so that developers can easily comprehend it for an easy fix. For this, you should write a good bug report that gives all the required information and is repeatable, which means that bugs can be reproduced invariably.

However, if you create a bug report, you must try to reproduce the bug on your own. Here are some aspects which should be included in the bug report to make it highly detailed.

• Descriptive Title: Start with a clear and descriptive title that gives a quick idea of what the bug is about.
• Concise Description: Be clear and concise in your description of the bug. Practice describing things accurately without making assumptions since the person reading it hasn't seen the bug.
• Expected Results: Clearly state what you expected to happen and how the actual result differed from your expectation. It prevents misunderstandings and helps developers understand what went wrong.
• Project and Version Details: Make sure your bug is listed in the correct project and section. Also, provide the correct software version. Developers may waste time if they are looking for a bug that has already been fixed or addressed in a different version.
• Platform Details: Provide any background information about your environment, such as the device, operating system, model, and browser version. These details help developers track down the bug more effectively.
• Defect Type and Severity: Categorize the bug correctly in terms of type and severity. Mentioning the priority and severity of the bug helps with the decision-making process on what gets fixed first.
• Steps to Reproduce: Provide a step-by-step account of what you did to encounter the bug. If possible, use tools to capture keystrokes, screenshots, or videos. Take notes as you test and retest your steps before submitting the bug. Indicate whether the bug occurs consistently, randomly, or only once.
• Visual Attachment: Include supporting materials like screenshots, audio, or video files. Developers often look at these first before reading the text, so a single screenshot that clearly shows the issue can save time.
• Tags & Links: Use descriptive tags to help categorize and filter related bugs. You can also include bug IDs or links to related reports, indicating the connection without duplicating the information.
• Assignee: Bug assignment is usually handled by the lead developer or management, but if you receive instructions on who to assign the bug to, make sure to follow them. Leaving unassigned or wrongly assigned bugs in the database can cause them to be overlooked.

Following the above guideline can help write good and comprehensive bug reports that effectively communicate the defects to developers and enhance quick bug fixing.

Detecting and Fixing Bugs on the Cloud

Detecting and fixing bugs can be carried out in traditional software development environments as well as in cloud-based platforms. To leverage the process of bug fixing in software development, it is recommended to use a cloud-based platform. Here are some practical reasons to choose cloud-based platforms.

• You can easily access bug-tracking tools from any location using a cloud-based platform. It helps develop good collaboration with team members and eases reporting and tracking of bugs. However, a traditional software development environment needs physical access to the bug-tracking system. It not only limits accessibility but hinders team collaboration.
• You get a seamless update and scalable options with a cloud-based platform, facilitating organizational adaptation to evolving bug management needs. You can also scale resources as necessary, ensuring effective bug tracking and resolution even in scenarios involving a high volume of bugs. However, in a traditional environment, you must perform manual updates and resource allocation, increasing complex bug management.
• The cloud-based platform integrates with automation tools that help streamline the detection and fixation of bugs. Conversely, the traditional environment has limited automation capabilities, requiring a manual approach to bug detection and resolution.
• You get a real-time update on a cloud-based bug-tracking system and help to monitor and track bugs. However, the traditional environment does not provide real-time updates, which makes bug tracking a time-consuming process.

In the Software Testing Life Cycle, the chances of cross-browser issues are common and, at the same time, very critical as they can directly impact the functionality of the software application. To address this, cross browser testing can help you identify and resolve browser-specific compatibility bugs efficiently and quickly.

The testing process emphasizes delivering software releases that are compatible with multiple browsers. It is to provide a seamless user experience across different browsers, devices, and platforms. Ensuring such compatibility is crucial so that you can access the website and application easily, regardless of OS or browsers you are using.

You can use a cloud-based digital experience testing platform like LambdaTest to improve and optimize cross browser testing. This platform allows you to run tests on different devices, browsers, and OS combinations like iOS, Chrome, and Android on a secure and reliable cloud grid.

You can subscribe to the LambdaTest YouTube Channel and get the latest tutorials around Selenium testing, Playwright, and more.

How to Detect and Fix Bugs using LambdaTest?

As mentioned above, LambdaTest helps you perform manual and automation testing of websites and mobile apps on over 3000+ browsers, versions, and OS. It provides various debugging options that highlight that it not only helps you with testing but also assists in debugging your software application. Here are some of those:

• LT Debug by LambdaTest is an amazing free developer tool that simplifies the debugging process. It can add, remove and modify the header, whether it is a request or response header. Blocking HTTP requests, performing network throttling, switching between different user agent strings, simulating web page experience, and performing cross-domain AJAX requests on the website are all possible with the LT Debug.
• LambdaTest gives you options to detect UI bugs in real-time by providing access to pre-installed developed tools on real devices and operating systems.
• If you are using test automation, you utilize different debugging options like Command logs, Console logs, Telemetry logs, and more to identify and debug issues.
• LambdaTest provides integration with bug-tracking tools to perform one-click bug logging while testing your software applications.

If you wish to try one-click bug logging in automation testing, refer to our support document, Mark as Bug in Automation testing.

Challenges in the Bug Life Cycle

When following the bug life cycle, there can be certain difficulties where tracking, reporting, and fixing the bugs may be challenging. To detect and fix bugs effectively and maintain defect life cycle workflow, knowing the underlying difficulty may be helpful to remove bugs successfully. Below are some discussed difficulties in the bug life cycle:

• It is challenging to control the bug because its tracking is done in real-time in the bug life cycle.
• The software development environment is dynamic, and following a single approach to managing the bug life cycle is difficult. This can lead to inefficiencies and issues in keeping track of all of the bugs.
• The bug life cycle models lack flexibility, making it difficult to adapt to different project requirements or software development approaches. Customizing the whole bug life cycle per specific project needs is difficult.
• You have limited visibility and insight about the status of bugs, which restricts the comprehensive reporting or analytics abilities.
• Managing complex projects with a bug life cycle becomes difficult due to many interconnected issues and dependencies. This difficulty arises due to a lack of required tools and mechanisms in defect life cycle workflow.
• The bug life cycle mainly depends on the manual approach of tracing, updating, and fixing bugs. This can be really time-consuming and prone to error.

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Best Practices for Bug Life Cycle Implementation

For addressing the difficulties in the bug life cycle, it is essential to incorporate certain best practices while testing software applications that help ensure the fixation of bugs before its release into the market. Some of those are explained in the below-mentioned points:

• Clear Understanding: The entire team must comprehensively understand the different states a defect can go through. It ensures that everyone knows the stages involved in managing a defect.
• Proper Documentation: It is important to document the defect life cycle effectively to avoid any confusion in the future. Clear and documented processes help maintain consistency and serve as a reference for team members.
• Clear Responsibilities: Each team member involved in the defect life cycle should clearly understand their respective responsibilities. This clarity ensures that tasks are assigned correctly and everyone knows their role in the defect management process. Clear responsibilities contribute to better results and smoother collaboration.
• Detailed Status Updates: When updating the status of a defect, it is important to provide sufficient details and reasons for the status change. It helps other team members working on the defect to understand the rationale behind the status update. Clear and detailed updates promote effective communication and collaboration among the team.
• Careful Handling of Defect Tracking Tool: The defect tracking tool should be handled with care to ensure consistency in the workflow of the defect life cycle. Handling the tool carefully helps prevent inconsistencies or errors in the defect management process.