Requirements Analysis

Requirement Types

Functional Requirements

What the system should DO.

• "Users can log in with email and password"
• "System sends order confirmation email"

Non-Functional Requirements

How the system should BEHAVE.

• Performance: "Page loads in < 2 seconds"
• Security: "Passwords stored with bcrypt"
• Scalability: "Supports 10,000 concurrent users"

Constraints

Limitations on the solution.

• "Must use existing authentication system"
• "Must run on AWS"

Analysis Techniques

Ask "Why?" Five Times

Uncover the real requirement.

Requirement: "Add export to Excel button"
Why? → "Users need to share reports"
Why? → "Finance reviews monthly sales"
Why? → "They compare against targets"
Why? → "To identify underperforming regions"
Real Need: Regional performance dashboard

SMART Criteria

Requirements should be:

• Specific: Clear and unambiguous
• Measurable: Can verify completion
• Achievable: Technically feasible
• Relevant: Aligned with goals
• Time-bound: Has deadline

Edge Case Analysis

• What happens with no data?
• What happens with too much data?
• What if the user is offline?
• What if permissions are denied?

Requirement Validation

• Is it testable?
• Is it achievable?
• Is it necessary?
• Is it consistent with other requirements?
• Is it complete?
• Is the priority clear?

Documenting Requirements

**REQ-001**: User Authentication

**Description**: Users must authenticate to access the system.

**Acceptance Criteria**:
1. Given valid credentials, user gains access
2. Given invalid credentials, user sees error
3. After 5 failed attempts, account is locked

**Priority**: Must Have
**Dependencies**: REQ-002 (User Management)