When we think about testing, we often imagine clicking through screens, running scripts, or finding bugs after something is built. But experienced testers know that testing can start earlier. Much earlier. That is what shift left testing is all about. It means getting involved early in the planning phase and helping improve the requirements before any development begins.

In this article, we will look at how testers can review and test requirements, why it matters, and what to look for.

Why review requirements early?

The earlier you catch a problem, the easier and cheaper it is to fix. If a requirement is unclear or missing important details, the code built from it is likely to have problems too. 

Here is why testing requirements is worth it:

  • Helps the team build the right feature or product from the start
  • Reduces the number of bugs found during and after the development phase
  • Helps testers plan their work and write better test cases
  • Creates a common understanding across the team

How can testers get involved?

You do not need a finished product or a test environment to help. All you need is access to the requirements or user stories and a chance to ask questions.

Here are a few ways to get involved early:

  • Join sprint planning meetings
  • Review user stories as soon as they are written (be in touch with the BA)
  • Ask for clarification when something does not make sense
  • Suggest potential test scenarios or edge cases

When testers are involved in these early steps, they can catch issues that others might miss and help avoid problems later in the process.

What should testers look for?

When reviewing a requirement, here are 5 simple checks that can make a big difference:

  1. Is it clear?

Is the requirement written in a way that everyone understands it the same way?

Unclear: The system should support project cost tracking.
Better: The system should allow users to assign expenses to specific project codes and generate a cost summary report grouped by project at the end of each month.

  1. Is it complete?

Does it include all the key details, including what should happen when something goes wrong?

  1. Is it testable?

Can you write a clear pass or fail test for this requirement?

Not testable: The system should provide useful financial reports.

Testable: The system should generate a monthly financial summary report that includes total revenue, total expenses, and net profit, and it should export correctly to PDF and Excel formats.

  1. Is it consistent?

Does it fit with the other requirements already defined? 

  1. Are the acceptance criteria clear?

Do we know exactly when this requirement is considered complete? If not, it will be hard to test and approve.

Writing Given-When-Then style scenarios can help here.

Helpful questions to ask when you focus on shift left testing

Here are a few good questions testers can use when reviewing requirements:

  • What happens if the user enters incorrect or missing data?
  • Are there any limits or rules that apply?
  • What are the expected success and failure outcomes?
  • How will we know if the app/product is working correctly?
  • Who will use this and what are the users trying to do?

Asking these kinds of questions helps fill in gaps and reduce misunderstandings before coding starts.

A simple example

Let’s say your team is working on a “Request Time Off” feature for an HR system.

Unclear requirement:
Employees should be able to request time off.

Better version:
When an employee selects a date range and submits the request, the system checks if they have enough leave balance. If they do, the request is sent to their manager for approval. If not, the employee sees an error message explaining why it could not be submitted.

By asking a few simple questions, the team can turn a vague sentence into something clear, complete, and testable.

Keep asking early

You do not need any tools or scripts to test requirements. All you need is a critical eye and the confidence to ask questions when something seems unclear.

The earlier you get involved, the more value you bring to the team.

Test smarter by starting sooner

Testing does not need to wait for working software. With a bit of curiosity and attention to detail, you can help improve quality before development even starts.

So the next time you see a new requirement or user story, ask yourself:

Is it clear? Can I test this? What is missing?

Asking these questions early is a simple way to apply shift left testing and helps your team build the right product while avoiding problems later on.