7 Common BRD Mistakes That Derail Projects (And How to Fix Them)

Why a Bad BRD Is So Expensive

The IBM Systems Sciences Institute found that fixing a requirements defect after deployment costs 100 times more than fixing it during the requirements phase. That statistic has been cited so often it's almost cliché — but it keeps getting cited because it keeps being true. Requirements errors compound. A vague requirement becomes a misbuilt feature. A misbuilt feature requires rework. Rework pushes the timeline. A delayed timeline creates pressure to cut scope. Cut scope means unhappy stakeholders. Unhappy stakeholders question the entire project.

The Business Requirements Document (BRD) is the first major artifact in any project. Its mistakes are the most expensive kind, because they travel forward into every subsequent phase. An engineer who builds to a wrong requirement isn't just wasting engineering time — they're building something that will need to be undone and rebuilt.

Here are the seven mistakes that show up most often in BRDs, what they look like in practice, and how to avoid them.

Mistake 1: Writing Solutions Instead of Requirements

What it looks like: "The system shall display a dropdown menu on the homepage that allows users to filter products by category." This sentence is a solution. It prescribes a dropdown menu — a specific UI implementation — rather than expressing the underlying business need.

The consequence: When you write solutions into a BRD, you lock designers and engineers into implementation decisions before they've had a chance to evaluate alternatives. You might get a dropdown when a search bar, faceted filters, or a tabbed category view would have served users better. You've optimized for the wrong thing — describing the how instead of the what.

The fix: Write requirements in terms of business need and user capability, not implementation. The correct version of the above requirement: "Users shall be able to narrow the product catalog by category to find relevant items efficiently." This tells design and engineering what outcome to achieve — and gives them the latitude to figure out the best way to achieve it.

A good test: if your requirement contains words like "button," "dropdown," "screen," "modal," or any specific technology name, it's probably a solution, not a requirement.

Mistake 2: Skipping Stakeholder Analysis

What it looks like: The BRD is written by the PM and reviewed by the project sponsor. The document gets approved. Development begins. Three weeks in, the compliance team flags that the feature needs audit logging. Customer support points out that they need an admin view that wasn't in scope. The legal team discovers a data retention requirement that affects the database architecture.

The consequence: Stakeholders who weren't involved during requirements gathering surface requirements during development or, worse, at launch. Each late discovery is expensive. Some cause significant rework. Some delay the launch. A few will require architectural changes that nobody budgeted for.

The fix: Before writing a single requirement, create a stakeholder register. List every group that will be affected by the project — not just those who will use the product, but those who will support it, approve it, audit it, or integrate with it. For each group, identify a representative, document their primary concerns, and schedule time to gather their requirements before the first BRD draft. Then circulate the draft to all stakeholders before sign-off, not just the sponsor.

Mistake 3: Vague Success Criteria

What it looks like: "The project will improve the user experience and increase customer satisfaction." This is the most common type of success criterion in BRDs — and it's nearly useless. You can't measure it. You can't test it. And when the project ends, you can't tell whether you achieved it.

The consequence: When success criteria are vague, everyone gets to define success in their own terms. The PM declares victory because the feature shipped. Engineering is satisfied because the code is clean. Business stakeholders are disappointed because the KPIs didn't move. The post-project review is full of conflicting perspectives on whether the project succeeded, and nobody learns anything actionable for next time.

The fix: Write SMART success criteria: Specific, Measurable, Achievable, Relevant, and Time-bound. "Reduce checkout abandonment rate from 68% to 55% within 90 days of launch." "Achieve an NPS score of 40+ on the new onboarding flow within 60 days." "Process 10,000 concurrent transactions with response times under 200ms." These criteria are testable, unambiguous, and give the project a clear definition of done.

Mistake 4: Ignoring Non-Functional Requirements

What it looks like: The BRD exhaustively documents what the system will do but says nothing about how well it will do it. No performance targets. No security requirements. No scalability expectations. No accessibility standards.

The consequence: Non-functional gaps show up in production, not in development. The system works fine for 50 concurrent users in testing and falls over at 5,000 in production. The security audit conducted three weeks before launch uncovers a fundamental architectural issue. The accessibility review reveals that half the application fails WCAG 2.1 AA, which is now a legal requirement in several markets. Each of these is a major, expensive problem that was entirely preventable at the requirements stage.

The fix: Non-functional requirements deserve their own section in every BRD. At minimum, address: performance (response times, throughput, load targets), security (authentication, authorization, data encryption, compliance standards), scalability (user growth expectations, data volume projections), availability (uptime requirements, disaster recovery), and accessibility (WCAG level, assistive technology support). These aren't engineering concerns — they're business decisions. Engineering implements them, but the business must define them.

Mistake 5: No Out-of-Scope Section

What it looks like: The BRD documents everything the project will deliver. It says nothing about what the project won't deliver.

The consequence: Scope creep begins immediately. Because the boundary between "in scope" and "out of scope" is never explicitly drawn, any reasonable-sounding request can be justified as necessary to fulfill the stated requirements. "The BRD says users can manage their accounts — doesn't that include account deletion?" "We documented reporting features — didn't that include the executive dashboard?" Without explicit out-of-scope declarations, these arguments are almost impossible to refute.

The fix: Add an "Out of Scope" section immediately after your in-scope requirements. For Phase 1 projects, document Phase 2 features here. Document integrations that were considered and deferred. Document use cases that are related but explicitly excluded. For each item, note the rationale. This section is often as valuable as the requirements themselves — possibly more so.

Mistake 6: Single-Author BRD

What it looks like: One person — usually the project sponsor, the lead BA, or the PM — writes the entire BRD. Others review it, but the document reflects one person's understanding of the business need.

The consequence: A single author's blind spots become the document's blind spots. Requirements from departments the author doesn't work closely with get underspecified. Use cases the author doesn't encounter personally get missed. Assumptions the author makes unconsciously never get examined. The result is a BRD that looks comprehensive but has systematic gaps that correspond to the author's vantage point.

The fix: Structure BRD creation as a collaborative process. Use one author to coordinate and write — but solicit requirements directly from representatives of each affected stakeholder group through structured interviews or workshops. Have section owners from different departments review the sections that affect them. Run a final review session with all stakeholder representatives before sign-off. The goal isn't to write by committee (which produces incoherent documents) — it's to ensure that one coherent document incorporates many perspectives.

Mistake 7: Treating the BRD as a One-Time Document

What it looks like: The BRD is written, approved, filed, and never updated again. The project evolves. Decisions are made. Requirements change. But the BRD still reflects the state of understanding from three months ago. By the time the project ships, the BRD bears only a passing resemblance to what was actually built.

The consequence: The BRD loses its utility as a reference document. When questions arise during development, nobody consults the BRD because everyone knows it's out of date. When the project ends, there's no accurate record of what was decided and why. When the next project starts, institutional knowledge from this project is lost — and the team starts from scratch.

The fix: Treat the BRD as a living document. Maintain a version history and changelog. When decisions are made that affect the requirements, update the BRD. Assign an owner who is responsible for keeping it current. Don't overwrite changed requirements — mark the change, note the date and reason, and preserve the previous version in the history. A BRD that evolves with the project is infinitely more valuable than one that accurately reflects a decision made at kickoff and nothing since.

BRD Review Checklist

Before approving any BRD, run through these ten questions. If the answer to any of them is "no" or "I'm not sure," the document needs more work before sign-off.

The Cost of Getting It Right Now vs. Getting It Wrong Later

Every hour spent avoiding these seven mistakes during requirements is an investment that returns ten to one hundred times during development, testing, and deployment. The conversation that feels tedious at the BRD review meeting — "should we add an out-of-scope section?" — prevents the emergency sprint three months later when someone realizes the scope has doubled without the timeline changing.

Good BRDs don't happen by accident. They happen when teams follow a deliberate process: collaborative stakeholder input, solution-agnostic requirement writing, measurable success criteria, explicit scope boundaries, and a commitment to treating the document as a living artifact rather than a one-time deliverable.

Get those seven things right, and your BRD becomes the single source of truth that keeps your project aligned from kickoff to launch.