Acceptance testing: Definition and types

What is acceptance testing?

Acceptance testing is the last step in the software development life cycle, where users test whether an application works as expected in the real world.

Consider it like the last exam for your software, done to understand whether your product is ready to graduate to production or needs to repeat the term.

Acceptance testing is not about looking for bugs in your software; it’s all about validating whether the software solves real-world business problems and meets the user expectations for which it was originally designed.

Acceptance testing occurs between system testing and when your software goes live. It serves as a bridge between technical testing and real-world usage and helps ensure that your software operates smoothly as soon as your first user comes online.

The goal of this testing is pretty straightforward: “Does the software do what it is expected to do?” This way, it helps in identifying some gaps between what the developers built and what users would like to use it for.

“In software testing, the earlier a bug is found, the cheaper it is to fix.” – Karen N. Johnson

According to a study from IBM, acceptance testing is capable of finding 90% of the defects. This helps save a lot of cost and effort, as fixing these defects can be 100 times more expensive once the application is deployed to production.

In this article, you will learn about acceptance testing, its various types, benefits, challenges, and some of the best practices that you can follow while performing it.

Types of acceptance testing

“The goal of a Software Tester is to find bugs, find them as early as possible, and make sure they are fixed.” – Software Testing Practices (International Journal of Computer Applications)

While the major focus of acceptance testing is on user satisfaction, it also covers other aspects of a successful software product. There are various types of acceptance testing. Each type is designed to validate different aspects of the system. This ensures that the software meets both business and user requirements.

These types of acceptance testing are as follows:

UAT is the most common type of acceptance testing, where end users act as testers and use the software in real-world conditions

User acceptance testing (UAT)

UAT is the most common type of acceptance testing, where end users act as testers and use the software in real-world conditions. They perform their usual day-to-day tasks to verify whether the software works as expected. Teams usually conduct UAT in a staging environment that mimics production.

If the team skips UAT and launches the software directly to end users, the business may face critical losses while fixing bugs through multiple iterations.

Operational acceptance testing (OAT)

Operational acceptance testing is a type of non-functional software testing. It ensures that the software is fully ready for release in a live production environment. The team performs this testing right after UAT, and it differs completely from it.

While UAT verifies whether the software meets user requirements or business goals, OAT focuses on checking the system’s operational readiness. It also assesses whether the system can be effectively supported and maintained by the operational and IT teams once it goes live.

OAT typically involves checking various crucial aspects of the system, including performance, accessibility, maintainability, backup and recovery, security, and monitoring and alerting. By checking these aspects, OAT reduces the chances of sudden business risks.

It also helps prevent operational issues and validates all non-functional requirements. This ensures that the system continues to work effectively in the production environment.

Business acceptance testing (BAT)

Business acceptance testing, sometimes referred to as business process acceptance testing, helps map the business goals and purpose of the created software. This testing primarily emphasizes the business logic, regulatory compliance, and overall value delivery (finance) rather than only focusing on understanding the end-user behavior.

For this testing, testers must have a core business understanding to be able to test the business requirements. If there is any gap in understanding the user’s business, stakeholders must be involved in the process, or proper business and domain-specific training must be provided to the testers.

Contract acceptance testing (CAT)

This type of testing follows a contract that states once the software goes into production, the team must run the tests within a specified time limit, and all tests must pass. It is especially useful in client-vendor relationships where both sides agree on specific deliverables.

Both parties create an SLA (service level agreement) that clearly states the client will release the payment only after approving the final software quality. CAT helps both sides resolve disputes and close the project smoothly, ensuring they agree on the expected outcomes.

Regulation acceptance testing (RAT)

Each country or region has its own predefined set of guidelines and regulations. Businesses must adhere to these while developing and deploying their solutions to production. This is especially crucial for sectors like healthcare, finance, and telecommunications.

Even a small breach in regulation can lead to significant losses. RAT ensures that the system adheres to all the industry regulations and legal standards.

The rule is quite simple: after the RAT, if the software does not adhere to the requirements, then the software is not released in the respective region. If the software is still released, the vendor will be solely responsible for the actions to come.

Alpha testing

Alpha testing is the prior stage to UAT, where the development or QA team tests the software product before passing it on to external users for testing. These tests help the developers and testers stay within a controlled environment, typically within the organization. They also help in saving effort that might come up if a bug is detected before UAT testing.

Beta testing

This is probably the most common testing that you might have heard of. In this type of testing, the end users (known as beta testers) conduct tests on the software in a production-like environment. After testing, users are expected to give proper feedback on the performance, bugs, flaws, and user experience. This feedback is then used by the developers and testers to bridge the gap between the current software and the user’s expected software.

Acceptance testing provides proper validation of the software so that it is now ready to go into production

Benefits of acceptance testing

“Program testing can be quite effective for showing the presence of bugs … but is hopelessly inadequate for showing their absence.” – Edsger W. Dijkstra

Acceptance testing provides proper validation of the software so that it is now ready to go into production. The benefits of acceptance testing are not limited to defect detection and mitigation—it also provides several other benefits:

Improved software quality

Since acceptance testing works more in line with the user’s requirements, it can detect a lot of issues that earlier testing stages may miss. Some of the features that it tests include usability problems, misaligned business logic, or incorrect workflow implementation. This ultimately leads to higher software quality.

Validation against requirements

The main purpose of acceptance testing is to validate that the software has all the features that were originally documented as business and functional requirements. It makes sure that the development outcome aligns with the stakeholders’ expectations and contractual requirements.

Reduced risk of failure post-release

As acceptance testing is performed right before the release to production, it helps identify and resolve all defects and issues. This ensures that the software is stable and ready before it goes live. This leads to a reduction in costly post-release failures, rollbacks, and emergency patches in the production environment.

Better stakeholder confidence

By performing acceptance testing, testers ensure that business stakeholders, such as product owners, business analysts, and clients, have sufficient proof of the system’s functionality. This confirms that the system works as intended. This is the kind of transparency businesses need to approve the software for final release.

Efficient change management

Acceptance testing helps in identifying the areas where the software might need some refinements. This is quite necessary for making informed decisions before the final production release to avoid any rework after the deployment.

While acceptance testing is vital for testing software readiness, it also comes with a lot of challenges.

Challenges of acceptance testing

While acceptance testing is vital for testing software readiness, it also comes with a lot of challenges. Understanding these challenges helps in the careful planning and execution of the acceptance testing cycles.

Unclear requirements

One of the biggest challenges in acceptance testing arises when business requirements are unclear, incomplete, or constantly changing. If the requirements are not clear to the testers, they may struggle to define proper acceptance criteria. This can lead to unexpected outcomes during testing.

Limited user involvement

Acceptance testing is highly useful for the end users and business stakeholders. But, due to some reasons like time constraints, lack of interest, and competing priorities, users might not be available to perform tests. This can ultimately lead to inadequate coverage and sometimes biased results.

Insufficient test data

One core requirement of acceptance testing is realistic and representative test data. Creating or acquiring this data can be difficult, especially when dealing with sensitive information, and this can lead to incomplete and inaccurate testing.

Communication gaps

Since the software development life cycle is a large process, it is quite common to have miscommunication between technical teams and business users. This miscommunication often leads to a misunderstanding of the acceptance criteria, test expectations, and defect severity.

These gaps are the prime reason for delayed acceptance and can damage stakeholders’ trust.

Lack of test automation support

While acceptance testing is primarily manual and user-driven, the lack of common automation tools for repetitive and regression-related tasks can reduce efficiency.

Acceptance testing best practices

To get the most out of acceptance testing, organizations must adhere to a set of best practices. These best practices are as follows:

Define clear acceptance criteria

Establish the acceptance criteria during the requirement-gathering phase. Make sure both business and technical stakeholders agree on it. This criteria is the foundation for test cases and determines what a successful outcome might look like.

Involve end users from the beginning

Engaging real users or client representatives early in the development process is important. It is especially valuable during the requirements validation phase. This ensures that the software aligns with the actual user requirements at all stages. Organizations should also conduct sessions or workshops with businesses to discuss the outcomes, test cases, and acceptance.

Bridging the gap between the technical team and the business is essential.

Maintain clear communication

Bridging the gap between the technical team and the business is essential. Everything that is being discussed should be properly documented in plain language. Moreover, feedback loops and clarification of roles and responsibilities should always be there to avoid misunderstanding and ensure alignment.

Create realistic and representative test scenarios

Whatever test cases you create should be based on real-world workflows and reflect how users will interact with the system. Using these realistic test cases improves test reliability and relevance.

Use a traceability matrix

Maintaining a traceability matrix between the requirements, test cases, and acceptance criteria can provide complete coverage and provide a clear audit trail. This matrix is quite useful for regulated industries like healthcare and finance, or contract-based acceptance testing.

Conclusion

After reading this article, you now know that acceptance testing works as a bridge between software development and deployment. It makes sure that the final software product aligns with real-world user needs and business requirements.

If your team performs acceptance testing effectively, it can improve the software quality.

Also, it can increase the stakeholders’ confidence in the software, and minimize the risk of post-production failures. Ultimately, strong acceptance testing ensures that the final delivered project is not just a working system but the right system.

This post was written by Gourav Bais. Gourav is an applied machine learning engineer skilled in computer vision/deep learning pipeline development, creating machine learning models, retraining systems, and transforming data science prototypes into production-grade solutions.