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Non-Functional Requirements (NFR)

Overview

This document defines the non-functional requirements for the Dispatch Center Application, covering performance, security, reliability, usability, maintainability, and operational requirements that ensure the system meets business and technical quality standards.

Table of Contents

Performance Requirements

Response Time Requirements

Operation Type Target Response Time Maximum Acceptable Performance Metric
Web Application Page Load < 2 seconds < 3 seconds Time to Interactive (TTI)
API Response (Simple Queries) < 500ms < 1 second Server response time
API Response (Complex Queries) < 2 seconds < 3 seconds End-to-end response time
Database Queries < 200ms < 500ms Query execution time
Service Request Creation < 1 second < 2 seconds Complete transaction time
Real-time Updates < 100ms < 300ms WebSocket/SignalR latency
Mobile App Launch < 3 seconds < 5 seconds Cold start time
Mobile Sync Operation < 10 seconds < 30 seconds Background sync completion

Throughput Requirements

Metric Target Peak Load Measurement Period
Concurrent Web Users 500 users 1,000 users Simultaneous active sessions
Concurrent Mobile Users 200 technicians 400 technicians Active mobile sessions
API Requests per Second 1,000 RPS 2,500 RPS Average over 1-minute intervals
Database Transactions 500 TPS 1,200 TPS Peak transaction volume
Service Request Processing 100/hour 300/hour Business transaction rate
Report Generation 50 concurrent 100 concurrent Simultaneous report requests

Resource Utilization

Resource Normal Load Peak Load Critical Threshold
CPU Utilization < 60% < 80% 90% (Alert threshold)
Memory Usage < 70% < 85% 95% (Critical threshold)
Database CPU < 50% < 75% 85% (Alert threshold)
Database Storage < 80% < 90% 95% (Expansion required)
Network Bandwidth < 60% < 80% 90% (Performance degradation)
Azure Service Bus < 1,000 messages/min < 5,000 messages/min 10,000 messages/min (Throttling)

Security Requirements

For comprehensive security details, see Security Documentation

Authentication and Authorization

Requirement Specification Implementation
User Authentication Multi-factor authentication (MFA) required Azure AD (Entra ID) with conditional access
Session Management JWT tokens with 8-hour expiration Automatic refresh with sliding expiration
Password Policy Minimum 12 characters, complexity requirements Azure AD password policies
Account Lockout 5 failed attempts trigger 30-minute lockout Azure AD smart lockout
Role-Based Access Granular permissions by user role Custom RBAC implementation
API Security OAuth 2.0 with scope-based access Azure API Management policies

Data Protection

Requirement Standard Implementation
Data Encryption at Rest AES-256 encryption Azure SQL Transparent Data Encryption
Data Encryption in Transit TLS 1.3 minimum Azure Application Gateway SSL termination
Secrets Management HSM-backed key storage Azure Key Vault with managed HSM
PII Protection Data masking and anonymization Custom data protection middleware
Audit Logging Immutable security audit trail Azure Monitor and Log Analytics
Data Retention Configurable retention policies Automated data lifecycle management

Network Security

Requirement Implementation Monitoring
Web Application Firewall Azure Application Gateway WAF Real-time threat detection
Network Segmentation Azure Virtual Network with NSGs Traffic flow monitoring
DDoS Protection Azure DDoS Protection Standard Attack mitigation reporting
Intrusion Detection Azure Security Center Automated threat response
Certificate Management Automated certificate rotation Expiration monitoring and alerts

Reliability and Availability Requirements

Availability Targets

Service Component Availability Target Downtime per Month Recovery Time Objective
Web Application 99.9% (8.6 minutes) < 43 minutes < 15 minutes
Mobile Application 99.5% (offline capable) N/A (offline mode) < 5 minutes (sync)
API Services 99.95% (4.3 minutes) < 22 minutes < 10 minutes
Database Services 99.99% (4.3 minutes) < 4.3 minutes < 5 minutes
Integration Services 99.5% (3.6 hours) < 3.6 hours < 30 minutes
Critical Operations 99.99% (4.3 minutes) < 4.3 minutes < 2 minutes

Fault Tolerance

Scenario Requirement Implementation
Single Point of Failure No single points of failure Multi-zone deployment with load balancing
Database Failover Automatic failover < 60 seconds Azure SQL Database auto-failover groups
Application Instance Failure Automatic recovery < 2 minutes Azure App Service with health checks
Regional Outage Disaster recovery < 4 hours Multi-region deployment with traffic manager
Data Backup Point-in-time recovery Automated backups with geo-redundancy
Message Queue Failure Message persistence and retry Azure Service Bus with dead letter queues

Data Durability

Data Type Backup Frequency Retention Period Recovery Point Objective
Transactional Data Continuous (point-in-time) 35 days < 15 minutes
Configuration Data Daily 90 days < 1 hour
Audit Logs Real-time replication 7 years < 5 minutes
User Files/Documents Hourly 30 days < 1 hour
Integration Data Daily 14 days < 4 hours

Scalability Requirements

Horizontal Scaling

Component Scaling Trigger Maximum Scale Auto-scaling Policy
Web App Instances CPU > 70% 20 instances Scale out: +2 instances, Scale in: -1 instance
API App Instances CPU > 70% or Queue depth > 100 30 instances Scale out: +3 instances, Scale in: -1 instance
Database DTUs DTU > 80% 4000 DTUs Automatic scaling with 10-minute evaluation
Service Bus Messaging Message rate > threshold Premium tier Partition scaling for throughput
Azure Functions Queue length > 50 200 instances Event-driven scaling

Vertical Scaling

Resource Baseline Peak Capacity Upgrade Trigger
Database Size 500 GB 4 TB 85% storage utilization
App Service Plan Standard S2 Premium P3V2 Sustained high CPU/memory
Cache Size 1 GB Redis 6 GB Redis Cache hit ratio < 90%
Storage Account Standard LRS Premium SSD IOPS requirements

Growth Projections

Metric Current Year 1 Year 3 Planning Considerations
Active Users 100 500 1,500 License and capacity planning
Service Requests/Month 1,000 5,000 15,000 Database and processing capacity
Data Storage 100 GB 500 GB 2 TB Storage tier and backup planning
API Calls/Day 10K 50K 200K Rate limiting and caching strategy
Mobile Devices 50 200 500 Push notification and sync capacity

Usability Requirements

Web Application Usability

Requirement Target Measurement Method
User Interface Response < 0.5 seconds for UI interactions User experience testing
Navigation Efficiency < 3 clicks to reach any function Task completion analysis
Learning Curve New users productive within 2 hours User training metrics
Error Recovery Clear error messages with guidance Usability testing feedback
Accessibility Compliance WCAG 2.1 AA compliance Automated accessibility testing
Browser Compatibility Latest 2 versions of major browsers Cross-browser testing

Mobile Application Usability

Requirement Target Implementation
Offline Functionality 100% core functions available offline Local SQLite storage
Touch Interface Minimum 44px touch targets Responsive design guidelines
Battery Optimization < 5% battery drain per hour Background task optimization
Data Usage < 10MB per day normal usage Efficient sync algorithms
One-Handed Operation Critical functions accessible with thumb Bottom navigation patterns
Voice Input Support Voice-to-text for notes and forms Platform speech recognition APIs

Accessibility Requirements

Standard Compliance Level Implementation
WCAG 2.1 AA compliance Automated testing and manual review
Section 508 Full compliance Accessibility testing integration
Screen Reader Support NVDA, JAWS, VoiceOver compatibility Semantic HTML and ARIA labels
Keyboard Navigation Complete keyboard accessibility Tab order and focus management
Color Contrast 4.5:1 minimum ratio Automated contrast validation
Font Scaling Up to 200% zoom support Responsive typography

Compatibility Requirements

Platform Compatibility

Platform Supported Versions Notes
Web Browsers Chrome 100+, Firefox 100+, Safari 15+, Edge 100+ Progressive enhancement approach
Mobile OS iOS 15+, Android 10+ React Native target platforms
Windows Windows 10 version 1903+ For development and admin tools
macOS macOS 11+ Development environment support

Integration Compatibility

System Interface Type Version Support
Reach REST API v2.1+
MaddenCo ERP SOAP/REST v3.0+
Treadnet Webhook/REST v1.5+
Dayforce REST API v1+
GeoTab REST API v8.0+
Merchant Partners REST API v2.0+

Maintainability Requirements

Code Quality

Metric Target Measurement Tool
Code Coverage > 80% Unit test coverage analysis
Cyclomatic Complexity < 10 per method Static code analysis
Technical Debt Ratio < 5% SonarQube analysis
Code Duplication < 3% Code analysis tools
Documentation Coverage > 90% public APIs Documentation generation tools

Development and Deployment

Requirement Target Implementation
Build Time < 5 minutes Optimized CI/CD pipelines
Deployment Time < 10 minutes Blue-green deployment strategy
Rollback Time < 2 minutes Automated rollback procedures
Environment Provisioning < 30 minutes Infrastructure as Code (Terraform)
Database Schema Updates Zero-downtime migrations Entity Framework Core migrations

Monitoring and Diagnostics

Capability Requirement Implementation
Application Monitoring Real-time performance metrics Azure Application Insights
Log Aggregation Centralized structured logging Azure Log Analytics
Distributed Tracing End-to-end request tracking OpenTelemetry integration
Health Checks Automated health monitoring Custom health check endpoints
Alerting Proactive issue notification Azure Monitor alerts

For detailed monitoring specifications, see Monitoring Documentation

Operational Requirements

Backup and Recovery

Component Backup Strategy Recovery Procedure
Application Data Automated daily backups with geo-redundancy Point-in-time restore capability
Configuration Version-controlled infrastructure code Automated environment recreation
User Files Real-time backup to Azure Blob Storage Self-service file recovery
Audit Logs Immutable log storage with long-term retention Query-based log retrieval
Database Automated backup with 35-day retention Geo-restore for disaster scenarios

Environment Management

Environment Purpose Deployment Frequency Data Refresh
Development Feature development and unit testing Continuous (on commit) Synthetic data
Testing Integration and system testing Daily Anonymized production subset
Staging Production validation and performance testing On release candidate Production mirror (anonymized)
Production Live operational environment Scheduled releases Live data

Capacity Planning

Resource Monitoring Threshold Capacity Planning Trigger Lead Time
CPU Usage 70% sustained 80% for 1 hour 1 week for scaling
Memory Usage 80% sustained 85% for 30 minutes 1 week for scaling
Storage 75% utilized 85% utilization 2 weeks for expansion
Network 70% bandwidth 80% for 1 hour 2 weeks for upgrade
Database DTU 70% sustained 80% for 1 hour 1 week for scaling

Compliance Requirements

Regulatory Compliance

Regulation Scope Requirements Implementation
GDPR Personal data processing Data protection and privacy rights Privacy by design, consent management
SOX Financial reporting Audit trails and controls Immutable audit logs, access controls
PCI DSS Payment processing Secure payment data handling Tokenization, encrypted storage
HIPAA Healthcare data (if applicable) Protected health information security Data encryption, access logging

Industry Standards

Standard Compliance Level Certification Audit Frequency
ISO 27001 Full compliance Certified Annual
SOC 2 Type II Full compliance Certified Annual
NIST Cybersecurity Framework Implementation Self-assessed Quarterly review

Mobile-Specific Requirements

Performance Requirements

Metric Target Maximum Platform
App Launch Time < 3 seconds < 5 seconds iOS/Android
Memory Usage < 150 MB < 200 MB iOS/Android
Battery Impact < 5% per hour < 10% per hour iOS/Android
Storage Usage < 100 MB < 200 MB iOS/Android
Network Efficiency < 1 MB per sync < 5 MB per sync iOS/Android

Offline Capabilities

Feature Offline Support Sync Strategy Conflict Resolution
View Service Requests Full support Background sync Server wins
Update Status Queue for sync Real-time when online Timestamp-based
Photo Capture Local storage Upload when connected Manual resolution
GPS Tracking Local logging Batch upload Append-only
Forms Completion Draft auto-save Submit when online User confirmation

Device Integration

Capability Requirement Implementation
GPS Location Continuous background tracking Platform location services
Camera Access Photo capture and barcode scanning Native camera APIs
Biometric Authentication Face ID/Touch ID/Fingerprint Platform biometric APIs
Push Notifications Real-time job notifications Azure Notification Hubs
Background Sync Periodic data synchronization Platform background tasks

Integration Requirements

External System Integration

For detailed integration specifications, see Integration Patterns Documentation

System Availability Requirement Response Time Error Handling
Reach 99.5% during business hours < 2 seconds Retry with exponential backoff
MaddenCo ERP 99.9% during business hours < 5 seconds Queue for later processing
Treadnet 99.0% (best effort) < 3 seconds Graceful degradation
Dayforce 99.9% (HR critical) < 2 seconds Immediate escalation
GeoTab 99.5% during operations < 1 second Cache last known positions
Merchant Partners 99.99% (payment critical) < 1 second Transaction rollback

API Gateway Requirements

Metric Target Implementation
Request Rate Limiting 1000 requests/minute per client Azure API Management policies
Authentication OAuth 2.0 with JWT tokens Azure AD integration
Monitoring Full request/response logging Azure Monitor integration
Caching Response caching for GET operations Redis-based caching
Transformation Request/response format conversion API Management policies

Document Version: 1.0
Last Updated: January 2026
Next Review: April 2026