Operational Acceptance Testing: A Quick Overview

What is operational acceptance testing?

Operational Acceptance Testing (OAT) is a type of software testing that checks whether a system is ready to run smoothly in the production environment.

Unlike functional testing, which focuses on whether the software or website performs as expected, OAT focuses on how well it operates once deployed.

In other words, OAT ascertains that the system is reliable and wouldn’t break when it’s live.

What’s the difference between OAT and UAT?

User Acceptance Testing (UAT) checks whether the software meets the agreed business requirements before it’s rolled out to users. It's done by end-users or business stakeholders to check whether it's usable, workflows run smoothly, and whether the product solves the problem it was designed to address.

Operational Acceptance Testing (OAT) comes later. It checks whether the system can run reliably in the real world.

Priorities include checking the system’s uptime, data recovery set ups, alert configs, and other routine tasks that happen behind the scenes but are essential to the user experience.

In short:

• UAT testing = Does the system meet business/user needs?
• OAT testing = Can this run without breaking, even when things go wrong?

These two types of testing helps you validate the usability and stability of your website.

What operational acceptance looks like for websites

Here’s an example of typical OAT tests:

1. Can the site handle a spike in traffic? To know this, the website owner needs to check if the hosting infrastructure can auto-scale, load balancers can distribute traffic evenly, and cache layers (like CDNs) reduce server load. ‍
2. Are backups working and restorable? To know this, you’d have to check if the database and file system are backed up at regular intervals. You also have to be sure you can restore them without losing data or experiencing extended downtime. ‍
3. Does server downtime trigger necessary alerts? To know this, your monitoring tools have to be connected to system metrics (e.g. CPU, memory, uptime) and send real-time notifications to the dev team when something fails. ‍
4. Is user data encrypted and stored correctly? This means encryption is in place for data at rest and data in transit, access controls are enforced, and compliance standards (like GDPR or HIPAA) are met.

These are just some ideas on what OAT looks like for website owners. They help you validate the operational readiness of your software or site:

Key elements of operational readiness

Operational readiness means your system can run, recover, and scale in a live environment without lag or operational issues.

Some of the key areas to test before going live include:

1. Disaster recovery tests

Disaster recovery tests check if the system can bounce back after a major failure. Think server crashes like Amazon’s back in 2018, data corruption, or outages like X’s. Tasks to run include:

• If there are enough servers to meet traffic demands.
• If the database and file backups are working.
• Attempt full or partial restores.
• Validate recovery time objectives (RTOs).

2. Security and compliance checks

This ensures the software meets internal security standards and legal requirements. This is important if you operate in finance, healthcare, or are an e-commerce brand.

Tasks for these checks include:

• Vulnerability scans.
• Access control testing.
• Encryption checks.
• Compliance audits (e.g. GDPR, HIPAA, etc.).

3. Performance & reliability tests

Here you test how well the system holds up under pressure and how it can consistently deliver a usable experience.

Tasks include:

• Load testing under peak traffic.
• Monitoring response times and error rates.
• Failover testing.

4. Maintenance tasks

You can also run checks to know whether the site or app can be updated, patched, and maintained without affecting users or existing workflows.

To do this:

• Deploy updates through staging to production environments to see how it responds.
• Run scheduled jobs (e.g. batch processes at night or any other off-peak hours).

5. Support readiness

This ensures that when issues arise, the right people are alerted, and have the information they need.

You can run tasks to:

• Validate monitoring and alerting tools.
• Test log visibility and traceability.
• Ensure support runbooks are up to date.

All these help you get the assurance that you need on the stability of your software before it's deployed in a live environment.

How to run operational acceptance testing

Since OAT shows how your website works when real users start engaging it, here’s how to approach it.

1. Define operational requirements early

Write what “ready for production” really means for your team, the website, and industry. For example, the uptime SLA for financial services is usually 99.99% – 99.999% while it’s 99.9% – 99.99% for e-commerce and healthcare services.

Your operational requirement can also be a 30 minutes recovery time (or any other number). This also means that whenever you have a downtime, your system must be back online within 30 minutes.

You need to have specific requirements so your team understands the acceptance criteria to work with.

2. Create test cases around real-life scenarios

Base your OAT on events that'll actually happen in the production environment. For example, test if the load balancer shifts traffic automatically when your web server goes down.

Can you restore your database entry from backup if it is deleted— without losing other data?

When a scheduled job fails, does the system alert the right person in time to fix it?

These are the scenarios you should think about, and each scenario should have an expected outcome to consider the test a success.

Read more: How to write test cases.

3. Validate monitoring and alert setups

Since operational readiness depends on visibility, set up real-time monitoring (CPU, memory, disk, uptime, traffic) to see if they trigger.

For example, deploy a test page that deliberately fails (e.g. 500 error). Does your alerting tool flag it? Do alerts reach the dev team or is it easily buried with other regular alerts?  

4. Test scheduled jobs and background tasks

Websites rely on scheduled tasks like cache, email queues, or database cleanups. These can fail silently, and it will affect user workflows.

So, disable the job that sends order confirmation emails and see if someone is notified of such action. Did a retry trigger? Can someone in support trace the failure?

All these tests mirror how actual people could use it in real life over time. Testing them increases your confidence that your system is stable.

Tools that streamline OAT

Operational acceptance testing uses the same tools already in place for QA and monitoring. However, you can add other tools to test reliability, find bugs or failures, and report issues fast.

1. For load testing, use tools like k6 or JMeter to simulate traffic spikes and see how your site performs under pressure.
2. For monitoring and alerts, use apps like Datadog, Sentry, or New Relic to track uptime, performance, and errors in real time.
3. For Backups and recovery, use AWS Backup or Veeam to automate snapshots so you can easily test restore scenarios.
4. For bug tracking and reporting, use Jira, ClickUp, or Asana to organize test results, track issues, and assign fixes.

You can also use Marker.io to help testers and stakeholders report issues directly from the live website. They can screenshot and annotate issues such as broken error states, missing alerts, or failed backups (or databases), and add context on what actually happened so the dev team can debug easily.

Read more about Marker.io features.

Wrapping up

In summary, Operational Acceptance Testing (OAT) helps you ascertain the reliability of your system under normal (and extraordinary) conditions.

It focuses on whether the website can stay online (when something on the backend crashes), if it can recover from failure (when a database fails), or if it operates as expected when actual people start using it.