Functional Requirements Functional Requirements Specification (FRS): {{PROJECT_NAME}} Project: {{PROJECT_NAME}} Version: {{VERSION}} Date: {{DATE}} Author: {{AUTHOR}} Status: Draft | In Review | Approved Reviewers: {{REVIEWERS}} Document History Version Date Author Changes 0.1 {{DATE}} {{AUTHOR}} Initial draft 1. System Overview System Name: {{SYSTEM_NAME}} System Purpose: {{PURPOSE_2_3_SENTENCES}} System Context Diagram: graph TB subgraph "{{SYSTEM_NAME}}" UI[Web / Mobile UI] API[Backend API] DB[(Database)] end U1[{{USER_TYPE_1}}] -->|Uses| UI U2[{{USER_TYPE_2}}] -->|Uses| UI API -->|Reads/Writes| DB API -->|Integrates| EXT1[{{EXTERNAL_SERVICE_1}}] API -->|Integrates| EXT2[{{EXTERNAL_SERVICE_2}}] ADM[Admin] -->|Manages| UI 2. Actors & Personas Actor ID Actor Name Type Description Access Level ACT-01 {{ACTOR_NAME}} Human / System {{DESCRIPTION}} {{ROLE/PERMISSIONS}} ACT-02 End User Human {{PERSONA_DESCRIPTION}} Authenticated user ACT-03 Administrator Human Manages system configuration and users Admin ACT-04 {{EXTERNAL_SYSTEM}} System External service integrated via API System Persona Detail Persona: {{PERSONA_NAME}} Role: {{JOB_TITLE}} Goal: {{PRIMARY_GOAL_USING_SYSTEM}} Pain Points: {{CURRENT_FRUSTRATIONS}} Tech Savviness: Low / Medium / High Frequency of Use: Daily / Weekly / Monthly 3. Functional Requirements 3.1 Module: {{MODULE_1_NAME}} Module Overview {{MODULE_DESCRIPTION}} FR-001: {{FEATURE_NAME}} Attribute Value Module {{MODULE_1_NAME}} Priority Must Have Trace BR-{{XXX}} UI Reference [Figma link or mockup filename] Description: {{FEATURE_DESCRIPTION_IN_BUSINESS_LANGUAGE}} Acceptance Criteria: Given {{PRECONDITION}}, when {{USER_ACTION}}, then {{EXPECTED_RESULT}} Given {{PRECONDITION}}, when {{USER_ACTION}}, then {{EXPECTED_RESULT}} Given invalid input, when {{USER_ACTION}}, then {{ERROR_HANDLING}} Data Requirements: Input: {{INPUT_DATA_FIELDS_AND_TYPES}} Output: {{OUTPUT_DATA}} Validation: {{VALIDATION_RULES}} Business Rules: RUL-{{XX}}: {{APPLICABLE_BUSINESS_RULE}} Dependencies: FR-{{XXX}}, DEP-{{XX}} FR-002: {{FEATURE_NAME}} Attribute Value Module {{MODULE_1_NAME}} Priority Must Have Trace BR-{{XXX}} UI Reference Description: {{FEATURE_DESCRIPTION}} Acceptance Criteria: Given {{PRECONDITION}}, when {{USER_ACTION}}, then {{EXPECTED_RESULT}} Given {{PRECONDITION}}, when {{USER_ACTION}}, then {{EXPECTED_RESULT}} Data Requirements: Input: {{INPUT}} Output: {{OUTPUT}} Validation: {{VALIDATION}} Business Rules: {{APPLICABLE_RULES}} Dependencies: {{DEPENDENCIES}} 3.2 Module: {{MODULE_2_NAME}} Module Overview {{MODULE_DESCRIPTION}} FR-010: {{FEATURE_NAME}} Attribute Value Module {{MODULE_2_NAME}} Priority Must Have Trace BR-{{XXX}} UI Reference Description: {{FEATURE_DESCRIPTION}} Acceptance Criteria: Given {{PRECONDITION}}, when {{USER_ACTION}}, then {{EXPECTED_RESULT}} Given {{PRECONDITION}}, when {{USER_ACTION}}, then {{EXPECTED_RESULT}} Data Requirements: Input: {{INPUT}} Output: {{OUTPUT}} Validation: {{VALIDATION}} Business Rules: {{APPLICABLE_RULES}} Dependencies: {{DEPENDENCIES}} 3.3 Module: Authentication & Authorization FR-020: User Registration Attribute Value Priority Must Have Trace BR-{{XXX}} Description: Users can create a new account using email and password. Acceptance Criteria: Given a valid email and password (≥8 chars, 1 uppercase, 1 number), when user submits registration form, then account is created and confirmation email is sent Given an already-registered email, when user tries to register, then system shows "Email already in use" error Given password does not meet complexity rules, when user submits, then inline validation error shown before submit Data Requirements: Input: email (unique), password, {{ADDITIONAL_FIELDS}} Output: user record, confirmation token Validation: email format, password complexity, duplicate check FR-021: User Login Attribute Value Priority Must Have Trace BR-{{XXX}} Description: Authenticated users can log in with email and password. Acceptance Criteria: Given valid credentials, when user submits login form, then user is authenticated and redirected to dashboard Given invalid credentials, when user submits, then generic error "Invalid email or password" is shown (no enumeration) Given 5 consecutive failed attempts, when user tries again, then account is temporarily locked for 15 minutes Given an authenticated session, when user is idle for 30 minutes, then session expires and user is redirected to login 3.4 Module: {{MODULE_N_NAME}} FR-030: {{FEATURE_NAME}} 4. Use Case Diagrams 4.1 {{MODULE_1_NAME}} Use Cases graph LR A1(({{ACTOR_1}})) --> UC1[FR-001: {{FEATURE}}] A1 --> UC2[FR-002: {{FEATURE}}] A2(({{ACTOR_2}})) --> UC3[FR-010: {{FEATURE}}] A2 --> UC4[FR-011: {{FEATURE}}] A3((Admin)) --> UC5[FR-020: {{FEATURE}}] A3 --> UC6[FR-021: {{FEATURE}}] 4.2 System-Level Use Case Overview graph LR subgraph "{{SYSTEM_NAME}}" UC1[{{MODULE_1}} Functions] UC2[{{MODULE_2}} Functions] UC3[Auth Functions] end ACT1(({{ACTOR_1}})) --> UC1 ACT1 --> UC3 ACT2(({{ACTOR_2}})) --> UC2 ACT2 --> UC3 ACT3((Admin)) --> UC1 ACT3 --> UC2 ACT3 --> UC3 5. System Behavior Specifications 5.1 Error Handling All user-facing errors must display a human-readable message (no stack traces) All errors must be logged with correlation ID, timestamp, user ID (if authenticated), and action Validation errors shown inline, adjacent to the invalid field System errors show generic message + contact info; full detail logged server-side only 5.2 Data Persistence All user-submitted data must be persisted within {{X}} seconds Optimistic UI updates must be rolled back if server confirmation fails All mutations (create/update/delete) must be audited with user ID and timestamp 5.3 Session & State Session timeout: {{X}} minutes of inactivity Concurrent session behavior: {{ALLOW/BLOCK/NOTIFY}} Browser refresh: application state must be restored from server 5.4 Notifications Email notifications: {{WHICH_EVENTS_TRIGGER_EMAILS}} In-app notifications: {{WHICH_EVENTS_TRIGGER_IN_APP}} Push notifications: {{IF_APPLICABLE}} Unsubscribe mechanism required for all marketing emails (GDPR) 5.5 Accessibility WCAG 2.1 Level AA compliance required Keyboard navigation for all interactive elements Screen reader compatibility (ARIA labels) Color contrast ratio ≥ 4.5:1 6. Requirements Summary Table ID Feature Name Module Priority Status Trace FR-001 {{FEATURE}} {{MODULE}} Must Have Draft BR-001 FR-002 FR-010 FR-020 User Registration Auth Must Have Draft BR-xxx FR-021 User Login Auth Must Have Draft BR-xxx Requirements Count: Must Have: {{COUNT}} Should Have: {{COUNT}} Could Have: {{COUNT}} Won't Have (this release): {{COUNT}} 7. Traceability to Business Requirements FR ID Feature Name Business Requirement (BR ID) Business Objective (BO ID) FR-001 {{FEATURE}} BR-{{XXX}} BO-{{XX}} FR-002 Full traceability matrix: [requirements-traceability-matrix.md](requirements-traceability-matrix.md) Approval Role Name Date Signature Author Reviewer Business Analyst Tech Lead Product Owner AI Director (John) Client Representative