Requirements are the foundation of every successful project. Yet so many Business Analysts, even experienced ones, write requirements that confuse developers, frustrate testers, and ultimately derail projects. The irony? Most of these mistakes are easy to fix once you know what to look for.
In my work with dozens of development teams, I’ve seen the same requirement problems pop up over and over. Let’s walk through the biggest culprits—and how to avoid them.
Mistake #1: Being Vague When You Should Be Specific
This is the heavyweight champion of requirement failures. A requirement like “The system should be fast” or “Users need an intuitive interface” sounds good in a meeting, but it’s useless when you’re actually building.
What to do instead: Translate vague language into measurable criteria. Instead of “fast,” say “Search results display within 2 seconds.” Instead of “intuitive,” describe the exact workflow: “Users should complete account setup in 3 clicks or fewer.”
Specific requirements leave no room for interpretation. Developers know exactly what to build. Testers know exactly what to verify.
Mistake #2: Mixing Functional and Non-Functional Requirements
I see requirements like: “The login button should be blue and allow users to authenticate.” You’ve just crammed functionality and design preference into one sentence, and now the developer doesn’t know what’s negotiable.
Separate them. Functional requirements describe what the system does. Non-functional requirements describe how well it does it:
- Functional: “Users can log in using email and password.”
- Non-functional: “The authentication API must respond in under 1 second. The login button must meet WCAG 2.1 AA color contrast standards.”
This clarity helps teams prioritize, trade off features, and scope work correctly.
Mistake #3: Assuming Context That Isn’t Written Down
You’ve been in stakeholder meetings. You understand the business problem. So you write: “Add a discount field to the order summary.” But which discount? When does it apply? Can users override it? Should it recalculate shipping?
The context is in your head, not on the page. When the developer asks, you’re shocked. “Of course it recalculates shipping—I said discount!”
Write it all down. Include acceptance criteria that spell out edge cases, exceptions, and assumptions. Use examples if needed.
Mistake #4: Writing Requirements That Are Actually Solutions
Your product manager says, “Users are abandoning carts because checkout is hard.” Your first instinct might be to prescribe the solution: “Add a one-page checkout process.”
But what if a two-step checkout with clear progress indicators would work better? You’ve locked the team into a solution that might not be optimal.
Write the problem: “Reduce cart abandonment by clarifying the checkout process and reducing perceived effort.” Let the design and dev team propose approaches.
Mistake #5: Forgetting About Constraints
Beautiful requirements that ignore technical reality are just fiction. I’ve seen BAs write requirements that assumed unlimited performance, budget, or timeline—then watched them die in development.
Know your constraints: technology limitations, regulatory requirements, budget, timeline. Build them into your requirements from the start. “The integration must work with our legacy billing system (API v2 only)” is way better than discovering mid-sprint that the shiny new approach is impossible.
Mistake #6: Not Including Acceptance Criteria
A requirement without acceptance criteria is just a wish. How will the dev team know when they’re done? How will QA know what to test?
Every requirement needs clear acceptance criteria. These are testable statements that prove the requirement is met:
- Given [context], when [user action], then [expected outcome]
- The system should [specific behavior] under [specific conditions]
This format (borrowed from Gherkin/BDD) forces clarity and gives testers a roadmap.
Mistake #7: Writing Requirements Only for the Happy Path
Everything works perfectly in your head. Payment processes succeed. API calls return data. Users enter valid information.
Real systems have unhappy paths: payment failures, timeouts, invalid input, permission errors. If your requirements ignore these scenarios, you’ll have a product full of surprises in production.
Always include: Error states, edge cases, timeout behavior, fallback workflows. What happens when the payment gateway is down? When the user enters a 200-character password?
Mistake #8: Skipping Stakeholder Sign-Off
You’ve written beautiful, specific requirements. But you moved straight to dev without confirming everyone agrees on what “done” looks like. Now halfway through, the product owner says, “Wait, that’s not what I meant.”
Get stakeholder sign-off before development starts. Use a simple template: “Is this what we agreed to? Any gaps? Sign here.” It takes 30 minutes and saves weeks of rework.
The Bottom Line
Good requirements aren’t fancy. They’re specific, testable, and documented. They explain the what and why, not the how. They account for constraints and edge cases. They’re signed off by stakeholders before work begins.
Master these habits, and your projects will move faster, with fewer surprises. Your developers will build the right thing. Your testers will know exactly what to verify.
If you’re looking for a framework to improve your requirements discipline, check out our free BA templates library—it includes requirement templates and acceptance criteria checklists that you can adapt to your team’s needs.
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