Non-Functional Requirements Document - StressLess Platform

Purpose

This Non-Functional Requirements (NFR) document defines the quality attributes, constraints, and operational characteristics for the StressLess platform. These requirements establish measurable criteria for system performance, security, scalability, and user experience that must be met to ensure successful platform deployment and operation.[1][2]

Scope

Non-functional requirements apply to all components of the StressLess platform, including the Progressive Web Application interface, local machine learning processing engine, data storage systems, and enterprise integrations. These requirements ensure the platform meets industry standards for workplace wellness solutions while maintaining superior privacy protection.[3][4]

Quality Attributes Framework

The NFRs are organized according to international standards (ISO/IEC 25010) and industry best practices for software quality characteristics:[2][1]

• Performance Efficiency: Response time, throughput, resource utilization

• Security: Confidentiality, integrity, availability, authentication

• Privacy: Data protection, consent management, regulatory compliance

• Reliability: Availability, fault tolerance, recoverability

• Scalability: Load handling, data volume growth, user expansion

• Usability: User experience, accessibility, learnability

• Compatibility: Platform support, integration capabilities

• Maintainability: Modifiability, testability, supportability

NFR-001: Response Time Performance

Requirement ID: NFR-001
Category: Performance Efficiency
Priority: Must Have

Detailed Requirements:

• NFR-001.1: Voice analysis processing shall complete within 3 seconds from recording completion to result display[5][1]

• NFR-001.2: Personal dashboard loading shall complete within 2 seconds for returning users with cached data[1]

• NFR-001.3: User interface interactions (button clicks, navigation) shall respond within 500 milliseconds [1]

• NFR-001.4: Real-time stress assessment feedback shall be provided within 1 second of analysis completion

• NFR-001.5: System login and authentication shall complete within 3 seconds including SSO verification

Measurement Criteria: Performance monitoring tools (Lighthouse, WebPageTest) with 95th percentile response time compliance Business Impact: Ensures user engagement and supports the platform's value proposition of "quick and easy" stress assessment

NFR-002: Throughput and Processing Capacity

Requirement ID: NFR-002
Category: Performance Efficiency
Priority: Must Have

Detailed Requirements:

• NFR-002.1: System shall process minimum 100 concurrent voice analyses per organization without performance degradation[1]

• NFR-002.2: Platform shall handle 10,000 daily voice assessments per 1,000-employee organization

• NFR-002.3: API endpoints shall support 500 requests per minute per organization

• NFR-002.4: Real-time analytics updates shall process within 30 seconds of data aggregation

• NFR-002.5: Bulk report generation shall complete within 10 seconds for standard organizational reports[1]

Measurement Criteria: Load testing with JMeter or similar tools under simulated production conditions Business Impact: Supports organizational scalability and ensures platform viability for enterprise deployments

NFR-003: Resource Utilization

Requirement ID: NFR-003
Category: Performance Efficiency
Priority: Should Have

Detailed Requirements:

• NFR-003.1: Voice analysis processing shall consume maximum 512MB RAM on user devices

• NFR-003.2: Local ML model storage shall not exceed 50MB device storage per user

• NFR-003.3: PWA application cache shall be limited to 100MB per user installation

• NFR-003.4: CPU utilization during voice processing shall not exceed 80% for more than 5 seconds

• NFR-003.5: Network bandwidth consumption shall be minimized through efficient data compression (target: <1MB per session)

Measurement Criteria: Device performance monitoring and resource usage analytics Business Impact: Ensures platform accessibility across diverse device capabilities and network conditions

NFR-004: Data Encryption and Protection

Requirement ID: NFR-004
Category: Security
Priority: Must Have

Detailed Requirements:

• NFR-004.1: All data at rest shall be encrypted using AES-256 encryption with secure key management[6][3]

• NFR-004.2: All data in transit shall use TLS 1.3 or higher with perfect forward secrecy[4][6]

• NFR-004.3: Voice analysis processing shall occur entirely on local devices with zero external data transmission [7]

• NFR-004.4: Cryptographic keys shall be generated using hardware-based random number generators where available

• NFR-004.5: Sensitive data (stress levels, personal insights) shall be encrypted with user-specific keys derived from authentication credentials

Measurement Criteria: Security audits, penetration testing, and cryptographic validation Business Impact: Establishes trust and competitive differentiation through superior data protection

NFR-005: Authentication and Access Control

Requirement ID: NFR-005
Category: Security
Priority: Must Have

Detailed Requirements:

• NFR-005.1: Multi-factor authentication (MFA) shall be required for administrative accounts[3]

• NFR-005.2: Single Sign-On (SSO) integration shall support SAML 2.0 and OpenID Connect protocols

• NFR-005.3: Session management shall implement secure session tokens with 30-minute idle timeout

• NFR-005.4: Role-based access control (RBAC) shall enforce principle of least privilege with granular permissions

• NFR-005.5: Password policies shall enforce minimum 12 characters with complexity requirements and breach detection

Measurement Criteria: Identity and Access Management (IAM) audits and security compliance assessments Business Impact: Ensures secure enterprise integration and protects against unauthorized access

NFR-006: Application Security

Requirement ID: NFR-006
Category: Security
Priority: Must Have

Detailed Requirements:

• NFR-006.1: Content Security Policy (CSP) shall be implemented to prevent Cross-Site Scripting (XSS) attacks[8][3]

• NFR-006.2: Cross-Site Request Forgery (CSRF) protection shall be implemented using secure tokens[3]

• NFR-006.3: Input validation and sanitization shall be applied to all user-provided data

• NFR-006.4: Secure coding practices shall be followed with regular static code analysis (SAST) and dynamic testing (DAST)

• NFR-006.5: Third-party dependencies shall be regularly scanned for known vulnerabilities using automated tools

Measurement Criteria: Security scanning tools (SonarQube, OWASP ZAP) and regular penetration testing Business Impact: Protects platform integrity and prevents security breaches that could damage reputation

NFR-007: GDPR Compliance Framework

Requirement ID: NFR-007
Category: Privacy and Compliance
Priority: Must Have

Detailed Requirements:

• NFR-007.1: Full compliance with General Data Protection Regulation (GDPR) for EU employee data processing[9][10][7]

• NFR-007.2: Data Processing Impact Assessments (DPIA) shall be conducted for all high-risk processing activities[9]

• NFR-007.3: Data subject rights (access, rectification, erasure, portability) shall be supported within 30 days of request[11]

• NFR-007.4: Consent management shall provide granular opt-in/opt-out controls with audit trails[11][9]

• NFR-007.5: Data breach notification procedures shall comply with 72-hour reporting requirements to supervisory authorities[9]

Measurement Criteria: Compliance audits by qualified Data Protection Officers and legal review Business Impact: Ensures regulatory compliance and avoids substantial GDPR fines (up to €20 million or 4% of global revenue)[9]

NFR-008: Data Minimization and Purpose Limitation

Requirement ID: NFR-008
Category: Privacy and Compliance
Priority: Must Have

Detailed Requirements:

• NFR-008.1: Data collection shall be limited to information necessary and relevant for stress monitoring purposes[11]

• NFR-008.2: Personal data shall be processed only for specified, explicit, and legitimate purposes[11]

• NFR-008.3: Data retention periods shall not exceed 2 years for organizational analytics and 90 days for individual voice sessions

• NFR-008.4: Automated data purging shall occur according to configured retention schedules with audit logging

• NFR-008.5: Purpose limitation controls shall prevent secondary use of employee data without explicit consent

Measurement Criteria: Data governance audits and privacy compliance assessments Business Impact: Minimizes privacy risks and demonstrates commitment to ethical data practices

NFR-009: Anonymization and Pseudonymization

Requirement ID: NFR-009
Category: Privacy and Compliance
Priority: Must Have

Detailed Requirements:

• NFR-009.1: Organizational analytics shall use fully anonymized data with minimum group sizes of 3 employees [5]

• NFR-009.2: Individual identifiers shall be pseudonymized using irreversible cryptographic techniques

• NFR-009.3: Re-identification risk assessment shall be conducted quarterly with mitigation measures

• NFR-009.4: Cross-departmental data correlation shall be prevented through technical and organizational measures

• NFR-009.5: Export functionality shall ensure no personally identifiable information is included in reports

Measurement Criteria: Privacy engineering assessments and anonymization effectiveness testing Business Impact: Enables organizational insights while maintaining individual privacy protection

NFR-010: System Availability

Requirement ID: NFR-010
Category: Reliability
Priority: Must Have

Detailed Requirements:

• NFR-010.1: System availability shall be 99.5% during business hours (6 AM - 10 PM local time)[12][1]

• NFR-010.2: Planned maintenance windows shall not exceed 4 hours per month with 48-hour advance notice

• NFR-010.3: Unplanned downtime shall not exceed 2 hours per month with maximum 1-hour continuous outages

• NFR-010.4: Core voice analysis functionality shall remain available offline without internet connectivity[13][4]

• NFR-010.5: System recovery time objective (RTO) shall be 4 hours for complete system restoration[1]

Measurement Criteria: Uptime monitoring tools and availability reporting dashboards Business Impact: Ensures reliable access for stress monitoring and maintains user trust in platform dependability

NFR-011: Fault Tolerance and Recovery

Requirement ID: NFR-011
Category: Reliability
Priority: Must Have

Detailed Requirements:

• NFR-011.1: System shall gracefully handle individual component failures without complete service disruption[12][1]

• NFR-011.2: Data backup procedures shall maintain Recovery Point Objective (RPO) of 15 minutes for user data

• NFR-011.3: Automated failover mechanisms shall activate within 30 seconds of primary service failure

• NFR-011.4: Error handling shall provide informative user messages without exposing sensitive system information[1]

• NFR-011.5: Circuit breaker patterns shall prevent cascade failures in integrated systems

Measurement Criteria: Disaster recovery testing and fault injection validation Business Impact: Protects against data loss and maintains service continuity during failures

NFR-012: Error Handling and Monitoring

Requirement ID: NFR-012
Category: Reliability
Priority: Should Have

Detailed Requirements:

• NFR-012.1: Application errors shall be logged with appropriate severity levels and contextual information

• NFR-012.2: Real-time monitoring shall detect and alert on system anomalies within 5 minutes

• NFR-012.3: User-facing error messages shall be clear, actionable, and avoid technical jargon[1]

• NFR-012.4: Performance degradation alerts shall trigger when response times exceed thresholds by 50%

• NFR-012.5: Comprehensive audit trails shall be maintained for all system operations and user actions

Measurement Criteria: Log analysis tools and monitoring dashboard effectiveness Business Impact: Enables proactive issue resolution and improves user experience through better error handling

NFR-013: User and Load Scalability

Requirement ID: NFR-013
Category: Scalability
Priority: Must Have

Detailed Requirements:

• NFR-013.1: System shall support 1,000+ concurrent users per organization without performance degradation[2][1]

• NFR-013.2: Platform shall accommodate organizations from 100 to 10,000 employees with linear scaling characteristics[12]

• NFR-013.3: Database performance shall maintain sub-second query response times for up to 1 million user records [2]

• NFR-013.4: Horizontal scaling shall be supported through containerization and cloud-native architecture

• NFR-013.5: Load balancing shall distribute traffic efficiently across multiple application instances

Measurement Criteria: Load testing with gradually increasing user loads and performance monitoring Business Impact: Enables enterprise market penetration and supports platform growth

NFR-014: Data Volume Scalability

Requirement ID: NFR-014
Category: Scalability
Priority: Must Have

Detailed Requirements:

• NFR-014.1: System shall handle 10,000+ daily voice assessments per organization without performance impact[1]

• NFR-014.2: Data storage architecture shall accommodate 12 months of historical data per user with efficient indexing

• NFR-014.3: Analytics processing shall scale to handle 1 million+ historical assessment records [2]

• NFR-014.4: Data archival processes shall maintain system performance as data volumes grow

• NFR-014.5: Search and reporting functionality shall maintain response times below 3 seconds regardless of data volume

Measurement Criteria: Database performance testing with production-scale data volumes Business Impact: Ensures long-term platform viability and supports comprehensive historical analysis

NFR-015: Geographic and Multi-Tenant Scalability

Requirement ID: NFR-015
Category: Scalability
Priority: Could Have

Detailed Requirements:

• NFR-015.1: Multi-region deployment shall support global organizations with <200ms latency targets

• NFR-015.2: Multi-tenant architecture shall isolate organizational data with shared infrastructure efficiency

• NFR-015.3: Content delivery networks (CDN) shall optimize resource loading for international users

• NFR-015.4: Time zone handling shall support global workforce with localized timestamps and scheduling

• NFR-015.5: Data residency requirements shall be met through regional data centers and compliance controls

Measurement Criteria: Geographic performance testing and multi-tenant isolation validation Business Impact: Enables global market expansion and supports multinational enterprise customers

NFR-016: User Experience and Interface Design

Requirement ID: NFR-016
Category: Usability
Priority: Must Have

Detailed Requirements:

• NFR-016.1: User interface shall be intuitive requiring no more than 5 minutes training for basic functionality[1]

• NFR-016.2: Voice assessment process shall be completable in 3 clicks or fewer from dashboard[2]

• NFR-016.3: Visual design shall maintain consistent branding and user experience across all screens

• NFR-016.4: Loading states and progress indicators shall be provided for operations exceeding 2 seconds

• NFR-016.5: Error prevention through input validation and clear user guidance shall minimize user mistakes

Measurement Criteria: User experience testing, task completion rates, and user satisfaction surveys Business Impact: Ensures high user adoption rates and reduces training and support costs

NFR-017: Accessibility and Inclusive Design

Requirement ID: NFR-017
Category: Usability
Priority: Must Have

Detailed Requirements:

• NFR-017.1: Platform shall comply with Web Content Accessibility Guidelines (WCAG) 2.1 Level AA standards[1]

• NFR-017.2: Keyboard navigation shall be fully supported for all interactive elements

• NFR-017.3: Screen reader compatibility shall be maintained with proper ARIA labels and semantic HTML

• NFR-017.4: Color contrast ratios shall meet 4.5:1 minimum for normal text and 3:1 for large text

• NFR-017.5: Alternative audio input methods shall be available for users with speech impairments

Measurement Criteria: Accessibility auditing tools (axe, WAVE) and testing with assistive technologies Business Impact: Ensures legal compliance and inclusive access for all employees

NFR-018: Mobile and Responsive Design

Requirement ID: NFR-018
Category: Usability
Priority: Must Have

Detailed Requirements:

• NFR-018.1: Responsive design shall support screen sizes from 320px to 4K displays with optimal layouts[4][13]

• NFR-018.2: Touch interface elements shall meet 44px minimum touch target size recommendations

• NFR-018.3: Mobile performance shall maintain 2-second page load times on 4G networks

• NFR-018.4: Progressive Web App features shall enable home screen installation and app-like experience[4]

• NFR-018.5: Offline functionality shall provide core features without internet connectivity[13][4]

Measurement Criteria: Cross-device testing and mobile performance audits Business Impact: Supports modern workforce mobility and flexible work arrangements

NFR-019: Browser and Platform Compatibility

Requirement ID: NFR-019
Category: Compatibility
Priority: Must Have

Detailed Requirements:

• NFR-019.1: Platform shall support current and previous major versions of Chrome, Firefox, Safari, and Edge browsers[4][2]

• NFR-019.2: Progressive Web App functionality shall be compatible with iOS 14+ and Android 8+ devices

• NFR-019.3: Voice recording capabilities shall function across all supported browsers with WebRTC compatibility

• NFR-019.4: Fallback mechanisms shall be provided for browsers with limited PWA support

• NFR-019.5: JavaScript compatibility shall maintain support for ES2018+ features with polyfill fallbacks

Measurement Criteria: Cross-browser testing automation and compatibility matrix validation Business Impact: Maximizes user base accessibility and reduces technical support requirements

NFR-020: Enterprise System Integration

Requirement ID: NFR-020
Category: Compatibility
Priority: Should Have

Detailed Requirements:

• NFR-020.1: Microsoft 365 integration shall support Graph API v1.0 with OAuth 2.0 authentication[14][15]

• NFR-020.2: HRIS system integration shall support SCIM 2.0 provisioning protocols

• NFR-020.3: REST API endpoints shall maintain OpenAPI 3.0 specification compliance

• NFR-020.4: Webhook notifications shall support HTTP/HTTPS delivery with retry mechanisms

• NFR-020.5: Data export formats shall include JSON, CSV, and PDF with consistent schemas

Measurement Criteria: Integration testing with common enterprise systems and API validation Business Impact: Facilitates enterprise adoption and reduces implementation complexity

NFR-021: Standards Compliance

Requirement ID: NFR-021
Category: Compatibility
Priority: Should Have

Detailed Requirements:

• NFR-021.1: Web standards compliance shall follow W3C recommendations for HTML5, CSS3, and JavaScript APIs

• NFR-021.2: Security standards shall align with OWASP Top 10 guidelines and NIST Cybersecurity Framework

• NFR-021.3: Data formats shall use ISO 8601 for timestamps and RFC 4122 for unique identifiers

• NFR-021.4: API design shall follow REST architectural principles and HTTP status code standards

• NFR-021.5: Accessibility standards shall maintain Section 508 and EN 301 549 compliance

Measurement Criteria: Standards validation tools and compliance certification processes Business Impact: Ensures interoperability and meets regulatory requirements for government and enterprise customers

NFR-022: Code Quality and Architecture

Requirement ID: NFR-022
Category: Maintainability
Priority: Should Have

Detailed Requirements:

• NFR-022.1: Code coverage shall maintain minimum 80% test coverage for critical business logic components

• NFR-022.2: Technical debt shall be managed with SonarQube quality gate compliance (A rating)

• NFR-022.3: Modular architecture shall enable independent deployment of major system components

• NFR-022.4: API versioning shall support backward compatibility for minimum 12 months

• NFR-022.5: Documentation shall be maintained with automated generation from code annotations

Measurement Criteria: Static code analysis tools and architecture quality assessments Business Impact: Reduces long-term maintenance costs and enables faster feature development

NFR-023: Deployment and DevOps

Requirement ID: NFR-023
Category: Maintainability
Priority: Should Have

Detailed Requirements:

• NFR-023.1: Continuous Integration/Continuous Deployment (CI/CD) pipeline shall enable automated deployments within 15 minutes [12]

• NFR-023.2: Blue-green deployment strategy shall enable zero-downtime updates for production systems[12]

• NFR-023.3: Infrastructure as Code (IaC) shall be used for reproducible environment provisioning

• NFR-023.4: Automated testing shall include unit, integration, and end-to-end test suites in CI pipeline

• NFR-023.5: Rollback procedures shall restore previous system version within 5 minutes of deployment issues

Measurement Criteria: Deployment automation metrics and release process efficiency analysis Business Impact: Enables rapid feature delivery and reduces deployment risks

NFR-024: Monitoring and Observability

Requirement ID: NFR-024
Category: Maintainability
Priority: Should Have

Detailed Requirements:

• NFR-024.1: Application performance monitoring (APM) shall provide real-time insights into system behavior

• NFR-024.2: Distributed tracing shall enable end-to-end request tracking across system components

• NFR-024.3: Log aggregation shall centralize logs with structured formatting and searchable interfaces

• NFR-024.4: Health check endpoints shall provide system status information for automated monitoring

• NFR-024.5: Performance baselines shall be established with automated alerting for deviation thresholds

Measurement Criteria: Monitoring coverage assessment and incident response time analysis Business Impact: Enables proactive issue detection and reduces mean time to resolution (MTTR)

NFR-025: Business Continuity and Disaster Recovery

Requirement ID: NFR-025
Category: Operational
Priority: Must Have

Detailed Requirements:

• NFR-025.1: Business Continuity Plan (BCP) shall ensure maximum 4-hour service restoration time[1]

• NFR-025.2: Data backup procedures shall maintain daily incremental and weekly full backups with offsite storage

• NFR-025.3: Disaster recovery testing shall be conducted quarterly with documented results

• NFR-025.4: Geographic redundancy shall protect against regional failures with automatic failover

• NFR-025.5: Communication procedures shall notify stakeholders within 30 minutes of major incidents

Measurement Criteria: Disaster recovery drill success rates and recovery time measurements Business Impact: Ensures business continuity and minimizes financial impact of service disruptions

NFR-026: Support and Documentation

Requirement ID: NFR-026
Category: Operational
Priority: Should Have

Detailed Requirements:

• NFR-026.1: User documentation shall be comprehensive and up-to-date with screenshot-based guidance

• NFR-026.2: API documentation shall include interactive examples and response schemas

• NFR-026.3: System administration guides shall cover installation, configuration, and troubleshooting procedures

• NFR-026.4: Knowledge base shall be searchable with categorized articles and video tutorials

• NFR-026.5: Support ticket system shall provide response time commitments based on severity levels

Measurement Criteria: Documentation completeness audits and user satisfaction surveys Business Impact: Reduces support costs and improves user self-service capabilities

Document Control
Next Review Date: September 27, 2025
Approval Required: Technical Lead, Security Officer, Privacy Officer, Quality Assurance Manager
Distribution: Development Team, DevOps Team, Security Team, Legal Team, Product Management

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