Requirements Document

A product requirements document, often called a PRD, explains what the team will build and why. It gives designers, engineers, and testers one shared source of truth. Everyone reads the same page, so fewer misunderstandings reach the final product.

Think of a PRD as the blueprint a builder reads before laying bricks. The blueprint does not show every nail. It shows the rooms, the purpose of each room, and the rules that keep the house safe. A PRD does the same for a feature.

The Standard PRD Layout

┌───────────────────────────────────────────────┐
│ 1. SUMMARY        One paragraph overview      │
│ 2. PROBLEM        Who struggles, and how      │
│ 3. GOALS          Measurable outcomes         │
│ 4. NON-GOALS      What the team will skip     │
│ 5. USERS          Who benefits                │
│ 6. REQUIREMENTS   What the product must do    │
│ 7. DESIGN         Sketches and flows          │
│ 8. RISKS          What could go wrong         │
│ 9. TIMELINE       Key dates and owners        │
│10. OPEN QUESTIONS Items still unanswered      │
└───────────────────────────────────────────────┘

Write Each Section Well

Summary

Give busy readers the full picture in three or four sentences. State the feature, the audience, and the expected result.

Problem

Describe the customer pain with evidence. Quote interviews, cite support tickets, and share usage numbers. A clear problem keeps the team honest about why the work matters.

Goals and Non-Goals

Goals name the results you want, such as "cut checkout time by 30 percent." Non-goals name tempting ideas you will not pursue in this release. Non-goals prevent the project from swelling.

Requirements

List what the product must do. Mark each item as must-have, should-have, or nice-to-have, so the team knows what to cut first when time runs short.

Risks and Open Questions

Admit what you do not know. Listing unknowns invites help from teammates and avoids unpleasant surprises later.

A Mini Example

FEATURE: Saved Searches

PROBLEM:   Shoppers repeat the same search every day
           (12% of sessions start with an identical query)

GOAL:      Raise returning-visitor rate from 22% to 28%

NON-GOAL:  Email alerts (planned for a later release)

REQUIREMENTS
  Must     Save a search with one tap
  Must     View saved searches on the home screen
  Should   Rename a saved search
  Nice     Share a saved search

RISK:      Too many saved items may slow the home screen
OPEN:      How many saved searches should each user get?

The PRD Review Flow

PM drafts PRD
     ↓
Designer reviews   → checks user flow and clarity
     ↓
Engineer reviews   → checks effort and technical risk
     ↓
Stakeholders review → check business fit
     ↓
PM updates PRD → team agrees → work begins

Tips for Strong Requirements

• Describe the need, not the technical solution
• Use plain words that a new teammate understands
• Make each requirement testable, so testers know when it passes
• Add visuals wherever a sketch replaces a paragraph
• Keep the document short; aim for two to four pages

Keep the PRD Alive

A PRD changes as the team learns. Record every update with a date and a short reason. Share changes in the team channel so nobody works from an outdated copy.

Common Mistakes

• Writing a long document nobody reads
• Skipping the problem and jumping to features
• Leaving goals vague, such as "improve the experience"
• Treating the PRD as final and refusing feedback

Who Reads the Document and Why

Each reader looks for a different answer. Engineers scan the requirements and risks to judge effort. Designers study the problem and user sections to shape the flow. Testers read the acceptance criteria and build their test cases from them. Marketers check the summary and goals to plan messaging.

Executives read the first paragraph and the timeline. Support teams read the requirements to prepare help articles before launch. Write with all of these readers in mind. Put the most important facts near the top of each section, label every section clearly, and link to deeper material and skip pasting it inline. A document that serves many readers saves many meetings.

Writing Style That Helps

Short sentences reduce confusion. Use active voice and name the actor in each requirement: "The user taps Save" beats "Save is tapped." Define special terms once and use them consistently. Add a small glossary when the document introduces unfamiliar words, and mark every assumption clearly so readers can challenge it early.

Key Takeaways

A PRD aligns the team around the problem, the goals, and the requirements. Keep it short, specific, and testable. Review it with design and engineering early, and update it as the team learns.