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)