# System Requirements Specification (SyRS) - Complete ## Centron Enterprise Application - System Requirements ### Document Information - **Document ID**: SyRS-CENTRON-2024-001 - **Version**: 1.0 - **Date**: September 30, 2024 - **Prepared by**: ISO 29148 System Requirements Analysis Agent - **Project**: UseCaseAnalyse (Centron Enterprise Application) - **Related Documents**: StRS_Complete.md (Stakeholder Requirements Specification) --- ## 1. Executive Summary ### 1.1 System Overview The Centron Enterprise Application is a comprehensive multi-layered .NET 8 enterprise business management system implemented using WPF for the client application with a dual-architecture pattern supporting both direct database access and web service communication. The system serves German-speaking enterprise markets with comprehensive CRM, financial management, helpdesk operations, project management, warehousing, and extensive third-party integrations. ### 1.2 System Context and Boundaries **System Boundary**: The system encompasses: - **WPF Client Application**: Desktop application providing rich user interface - **Web Service Layer**: REST API enabling web-based access and integrations - **Business Logic Layer**: Core business process implementation - **Data Access Layer**: NHibernate-based ORM with SQL Server backend - **External API Integration Layer**: 8 external service integrations - **Shared Component Layer**: Common UI controls and core functionality **External Systems**: FinAPI (banking), GLS/Shipcloud (shipping), ITscope/Icecat/Egis (product data), EbInterface (invoicing) ### 1.3 Architectural Principles - **Dual Data Access Pattern**: ILogic interface with BL (database) and WS (web service) implementations - **Dependency Injection**: Castle Windsor container managing service lifetimes - **Modular Design**: Plugin-based module system with dynamic loading - **Multi-Language Support**: German primary with English localization - **Security-First**: Comprehensive GDPR compliance and enterprise security --- ## 2. System Architecture Requirements ### 2.1 Architectural Structure Requirements #### 2.1.1 Multi-Layer Architecture **SyR-001**: The system SHALL implement a multi-layered architecture with clear separation of concerns - **Client Layer**: WPF UI application (src/centron/) - **Business Logic Layer**: Core business functionality (src/backend/Centron.BL/) - **Data Access Layer**: ORM and database interaction (src/backend/Centron.DAO/) - **Entity Layer**: Domain object models (src/backend/Centron.Entities/) - **Web Service Layer**: REST API implementation (src/webservice/) - **Integration Layer**: External API clients (src/apis/) - **Shared Layer**: Common components and controls (src/shared/) #### 2.1.2 Dual Data Access Pattern **SyR-002**: The system SHALL implement the ILogic interface pattern with dual implementations - **BL{Module}Logic**: Direct database access via NHibernate - **WS{Module}Logic**: Web service access via REST API - **ClassContainer**: Dependency injection managing implementation selection - **Connection Types**: CentronConnectionType.SqlServer and CentronConnectionType.CentronWebServices #### 2.1.3 Module System Architecture **SyR-003**: The system SHALL provide a plugin-based module system with dynamic loading - **ICentronAppModuleController**: Module lifecycle management interface - **BaseModule**: WPF UserControl base class for module views - **IRibbonControlModule**: Ribbon interface integration - **ModuleRegistration**: Centralized module registry with rights-based access ### 2.2 Technology Stack Requirements #### 2.2.1 Core Framework Requirements **SyR-004**: The system SHALL be built on Microsoft .NET 8 framework **SyR-005**: The system SHALL use Windows Presentation Foundation (WPF) for client UI **SyR-006**: The system SHALL use NHibernate ORM with FluentNHibernate for database access **SyR-007**: The system SHALL use DevExpress 24.2.7 for advanced UI controls **SyR-008**: The system SHALL use SQL Server as the primary database platform #### 2.2.2 External Dependencies **SyR-009**: The system SHALL use Castle Windsor for dependency injection **SyR-010**: The system SHALL use NLog for comprehensive logging **SyR-011**: The system SHALL use FastReport for report generation **SyR-012**: The system SHALL use Bullseye for build orchestration --- ## 3. Functional System Requirements ### 3.1 User Management and Security System #### 3.1.1 Authentication System **SyR-013**: The system SHALL provide secure user authentication with multi-factor authentication support - Windows Active Directory integration - Username/password authentication - Multi-factor authentication options - Session management with configurable timeout **SyR-014**: The system SHALL implement comprehensive role-based access control - Granular permission system via UserRightsConst - Hierarchical rights inheritance - Group-based permission management - Real-time rights validation #### 3.1.2 User Interface System **SyR-015**: The system SHALL provide a modern, responsive user interface optimized for business workflows - DevExpress-based controls and themes - Customizable dashboards and layouts - Consistent UX patterns across modules - Accessibility compliance support **SyR-016**: The system SHALL support comprehensive localization - German as primary language (LocalizedStrings.resx) - English localization support (LocalizedStrings.en.resx) - Locale-aware formatting for dates, numbers, currency - Runtime language switching capability ### 3.2 Customer Relationship Management System #### 3.2.1 Customer Data Management **SyR-017**: The system SHALL maintain comprehensive customer profiles with complete history tracking - Customer entity management (Centron.Entities) - Contact person and relationship mapping - Interaction history and communication tracking - Customer-specific settings and preferences **SyR-018**: The system SHALL provide advanced search and filtering capabilities - Full-text search across customer data - Multi-criteria filtering with saved preferences - Real-time search results with performance optimization - Export capabilities for search results #### 3.2.2 Sales Process Management **SyR-019**: The system SHALL support complete quote-to-order lifecycle management - Quote generation with approval workflows - Order conversion and processing - Status tracking and notifications - Integration with inventory and fulfillment **SyR-020**: The system SHALL provide automated pricing and discount calculation - Rule-based pricing engine - Volume discount calculations - Approval requirements for special pricing - Comprehensive pricing audit trails ### 3.3 Financial Management System #### 3.3.1 Receipt and Invoice Processing **SyR-021**: The system SHALL provide comprehensive receipt and invoice processing - Invoice generation with German compliance formatting - Receipt processing and validation - Tax calculations with German tax regulations - Multi-currency support with exchange rate management **SyR-022**: The system SHALL support automated payment processing and reconciliation - Bank integration via FinAPI - Automated payment matching - SEPA payment processing - Exception handling and manual reconciliation support #### 3.3.2 Financial Reporting and Analytics **SyR-023**: The system SHALL provide comprehensive financial reporting and analysis - Standard financial reports (P&L, Balance Sheet, Cash Flow) - Custom reporting with FastReport integration - Drill-down analysis capabilities - Export to multiple formats (PDF, Excel, CSV) ### 3.4 Helpdesk and Support System #### 3.4.1 Ticket Management **SyR-024**: The system SHALL provide comprehensive ticket lifecycle management - Ticket creation from multiple channels (email, phone, web) - Automated routing and assignment - SLA monitoring and escalation - Resolution tracking and documentation **SyR-025**: The system SHALL support automated ticket routing and escalation - Rule-based routing engine - SLA-based automatic escalation - Notification system for stakeholders - Performance metrics and reporting #### 3.4.2 Knowledge Management **SyR-026**: The system SHALL provide integrated knowledge base functionality - Searchable knowledge articles - Article lifecycle management - Customer self-service access - Usage analytics and improvement tracking ### 3.5 Project Management System #### 3.5.1 Project Lifecycle Management **SyR-027**: The system SHALL support comprehensive project planning and execution - Project templates and standardization - Task management with dependencies - Resource allocation and scheduling - Progress tracking and reporting **SyR-028**: The system SHALL provide project reporting and analytics - Project performance dashboards - Resource utilization reports - Budget tracking and variance analysis - Timeline and milestone reporting ### 3.6 Integration System Requirements #### 3.6.1 External API Integration Framework **SyR-029**: The system SHALL provide robust external service integration capabilities - RESTful API client implementations (src/apis/) - Standardized authentication handling - Error handling and retry mechanisms - Real-time monitoring and alerting **SyR-030**: The system SHALL support real-time data synchronization - Conflict resolution mechanisms - Data consistency validation - Synchronization status monitoring - Error recovery and rollback capabilities #### 3.6.2 Banking and Financial Integration **SyR-031**: The system SHALL integrate with German banking systems - FinAPI integration for automated banking - SEPA payment support - Transaction import and reconciliation - Compliance with German banking regulations --- ## 4. Non-Functional System Requirements ### 4.1 Performance Requirements #### 4.1.1 Response Time Requirements **SyR-032**: The system SHALL provide response times of less than 2 seconds for 95% of user interactions - Database query optimization with NHibernate - UI responsiveness with async/await patterns - Caching strategies for frequently accessed data - Performance monitoring and alerting **SyR-033**: The system SHALL support concurrent access by up to 500 simultaneous users - Connection pooling and management - Session state management - Resource optimization and cleanup - Load balancing capabilities #### 4.1.2 Throughput Requirements **SyR-034**: The system SHALL process up to 10,000 transactions per hour during peak periods - Batch processing capabilities - Queue management for high-volume operations - Database optimization for transaction processing - Performance scaling and monitoring ### 4.2 Scalability Requirements #### 4.2.1 System Scalability **SyR-035**: The system SHALL scale to support up to 1,000 registered users - User capacity management - Resource allocation scaling - Database performance under user load - Memory and CPU utilization optimization **SyR-036**: The system SHALL handle databases up to 1TB in size with acceptable performance - Database partitioning strategies - Index optimization and maintenance - Archive and purge strategies - Storage performance monitoring ### 4.3 Reliability and Availability Requirements #### 4.3.1 System Availability **SyR-037**: The system SHALL provide 99.5% uptime during business hours (8 AM - 6 PM CET) - High availability architecture design - Redundancy and failover mechanisms - Monitoring and alerting systems - Disaster recovery procedures **SyR-038**: The system SHALL support planned maintenance with maximum 4-hour downtime - Rolling update capabilities - Maintenance scheduling system - User notification mechanisms - Rollback procedures for failed updates #### 4.3.2 Data Reliability **SyR-039**: The system SHALL provide automatic data backup with point-in-time recovery - Automated backup scheduling - Transaction log backup strategies - Point-in-time recovery capabilities - Backup verification and testing ### 4.4 Security Requirements #### 4.4.1 Data Security **SyR-040**: The system SHALL encrypt all sensitive data at rest and in transit - Database encryption with TDE (Transparent Data Encryption) - Transport encryption with TLS 1.3 - Application-level encryption for sensitive fields - Key management and rotation policies **SyR-041**: The system SHALL maintain comprehensive audit logs - User activity logging - Data modification tracking - Security event monitoring - Log retention and compliance reporting #### 4.4.2 Access Security **SyR-042**: The system SHALL implement session management with automatic timeout - Configurable session timeouts - Concurrent session management - Session hijacking prevention - Secure session termination ### 4.5 Usability Requirements #### 4.5.1 User Experience **SyR-043**: The system SHALL provide intuitive navigation with minimal training requirements - Consistent UI patterns and workflows - Context-sensitive help and guidance - Progressive disclosure of complexity - User customization capabilities **SyR-044**: The system SHALL support accessibility standards - WCAG 2.1 compliance - Keyboard navigation support - Screen reader compatibility - High contrast and font scaling support ### 4.6 Compatibility Requirements #### 4.6.1 Platform Compatibility **SyR-045**: The system SHALL support Windows 10 and Windows 11 operating systems - OS compatibility testing and validation - Hardware requirement specifications - Driver and dependency management - Update and patch compatibility **SyR-046**: The system SHALL provide web browser compatibility - Chrome, Firefox, and Edge support for web components - HTML5 and CSS3 compliance - JavaScript compatibility and optimization - Mobile browser support for responsive components ### 4.7 Compliance Requirements #### 4.7.1 Data Protection Compliance **SyR-047**: The system SHALL comply with GDPR/DSGVO requirements - Data subject rights implementation (Administration/DSGVO module) - Consent management and tracking - Data breach notification capabilities - Privacy by design implementation **SyR-048**: The system SHALL comply with German tax and accounting regulations - German invoice formatting and requirements - Tax calculation and reporting compliance - Audit trail requirements - Document retention compliance --- ## 5. System Interface Requirements ### 5.1 Internal Interface Requirements #### 5.1.1 Layer Interface Requirements **SyR-049**: The system SHALL implement standardized interfaces between architectural layers - **ILogic Interfaces**: Standardized business logic contracts - **DAO Interfaces**: Data access object contracts with NHibernate - **Entity Interfaces**: Domain model contracts and relationships - **Service Interfaces**: Cross-cutting service contracts #### 5.1.2 Module Interface Requirements **SyR-050**: The system SHALL provide standardized module integration interfaces - **ICentronAppModuleController**: Module lifecycle management - **IRibbonControlModule**: UI integration contracts - **IBaseModule**: Common module functionality contracts - **IModuleSettings**: Module configuration interfaces ### 5.2 External Interface Requirements #### 5.2.1 Database Interface Requirements **SyR-051**: The system SHALL provide robust database connectivity and management - **NHibernate Configuration**: Automated configuration generation - **Connection Management**: Multi-database connection support - **Transaction Management**: ACID transaction support with rollback - **Schema Management**: Database migration and versioning #### 5.2.2 Web Service Interface Requirements **SyR-052**: The system SHALL provide comprehensive REST API interfaces - **ICentronRestService**: Complete API contract definition - **Authentication Interfaces**: OAuth 2.0 and token-based authentication - **Request/Response DTOs**: Standardized data transfer objects - **Error Handling**: Consistent error response patterns #### 5.2.3 External API Integration Interfaces **SyR-053**: The system SHALL provide standardized external service integration - **FinAPI Integration**: Banking and financial services (Centron.APIs.FinAPI) - **Shipping Integrations**: GLS and Shipcloud logistics (Centron.Api.Gls, Centron.Api.Shipcloud) - **Product Data Integrations**: ITscope, Icecat, Egis data services - **Invoice Integration**: EbInterface electronic invoicing --- ## 6. System Data Requirements ### 6.1 Data Architecture Requirements #### 6.1.1 Entity Relationship Requirements **SyR-054**: The system SHALL implement comprehensive domain entity relationships - **Customer Entities**: Customer, ContactPerson, Address hierarchies - **Financial Entities**: Receipt, Invoice, Payment, AccountTransaction relationships - **Support Entities**: Ticket, Task, Knowledge Article, Escalation relationships - **Project Entities**: Project, Task, Resource, Timeline relationships #### 6.1.2 Data Integrity Requirements **SyR-055**: The system SHALL enforce data integrity at all levels - **Primary Key**: Every table must have I3D [int] IDENTITY(1,1) NOT NULL - **Foreign Key**: All relationships must end with I3D suffix - **Standard Columns**: CreatedByI3D, CreatedDate, ChangedByI3D, ChangedDate, IsDeleted - **Data Validation**: Entity-level and database-level constraint enforcement ### 6.2 Data Storage Requirements #### 6.2.1 Database Design Requirements **SyR-056**: The system SHALL implement optimized database design patterns - **Normalized Design**: Third normal form compliance with performance exceptions - **Indexing Strategy**: Query performance optimization with maintenance balance - **Partitioning**: Large table partitioning for performance and maintenance - **Archiving**: Historical data archiving with retention policies #### 6.2.2 Data Migration Requirements **SyR-057**: The system SHALL provide automated data migration capabilities - **Schema Scripts**: Versioned database schema migration (BaseScriptMethod) - **Data Migration**: Automated data transformation and migration - **Rollback Support**: Migration rollback and recovery procedures - **Validation**: Post-migration data integrity validation --- ## 7. System Quality Attributes ### 7.1 Maintainability Requirements #### 7.1.1 Code Quality Requirements **SyR-058**: The system SHALL implement high-quality code standards - **SOLID Principles**: Single responsibility, open/closed, Liskov substitution, interface segregation, dependency inversion - **Clean Architecture**: Clear separation of concerns with dependency inversion - **Code Documentation**: Self-documenting code with minimal necessary comments - **Testing**: Comprehensive unit, integration, and end-to-end testing #### 7.1.2 Configuration Management Requirements **SyR-059**: The system SHALL provide comprehensive configuration management - **Application Settings**: Centralized settings management (ApplicationSettings table) - **Environment Configuration**: Environment-specific configuration support - **Runtime Configuration**: Dynamic configuration updates without restart - **Configuration Validation**: Settings validation and error handling ### 7.2 Portability Requirements #### 7.2.1 Platform Portability **SyR-060**: The system SHALL support deployment flexibility within Windows ecosystem - **Standalone Deployment**: Self-contained WPF application deployment - **Web Service Deployment**: Windows Service and Console host deployment - **Database Portability**: SQL Server version compatibility - **Environment Portability**: Development, testing, and production environment support ### 7.3 Testability Requirements #### 7.3.1 Testing Framework Support **SyR-061**: The system SHALL provide comprehensive testing support - **Unit Testing**: Isolated component testing with dependency injection - **Integration Testing**: Cross-component and database integration testing - **End-to-End Testing**: Complete workflow testing with UI automation - **Performance Testing**: Load and stress testing capabilities --- ## 8. System Constraints and Assumptions ### 8.1 Technical Constraints #### 8.1.1 Platform Constraints **TC-001**: The system is constrained to .NET 8 framework and Windows platform **TC-002**: The system requires SQL Server database platform **TC-003**: The system requires DevExpress licensing for UI components **TC-004**: External API integrations depend on third-party service availability #### 8.1.2 Architectural Constraints **TC-005**: The dual data access pattern requires synchronized interface contracts **TC-006**: Module system requires adherence to plugin architecture patterns **TC-007**: Localization requires UTF-8 with BOM encoding for all source files **TC-008**: Security implementation must comply with German and EU regulations ### 8.2 Business Constraints #### 8.2.1 Regulatory Constraints **BC-001**: The system must comply with German and EU regulatory requirements **BC-002**: The system is primarily designed for German-speaking markets **BC-003**: Financial compliance requires adherence to German accounting standards **BC-004**: Data protection must comply with GDPR/DSGVO requirements ### 8.3 Technical Assumptions #### 8.3.1 Infrastructure Assumptions **TA-001**: Target environment provides reliable SQL Server connectivity **TA-002**: Network infrastructure supports REST API communication **TA-003**: External service providers maintain API stability and availability **TA-004**: Hardware infrastructure meets performance requirements #### 8.3.2 Development Assumptions **TA-005**: Development team has expertise in .NET 8 and WPF technologies **TA-006**: DevExpress licensing and support will continue **TA-007**: External API providers will maintain backward compatibility **TA-008**: Database schema evolution will follow established migration patterns --- ## 9. System Verification and Validation ### 9.1 Verification Requirements #### 9.1.1 Functional Verification **SyV-001**: All functional requirements shall be verified through automated testing - Unit tests for business logic components - Integration tests for data access and external API integrations - UI automation tests for user workflows - Performance tests for scalability requirements #### 9.1.2 Non-Functional Verification **SyV-002**: All non-functional requirements shall be verified through systematic testing - Performance benchmarking and load testing - Security penetration testing and vulnerability assessment - Usability testing with representative users - Compliance auditing and validation ### 9.2 Validation Requirements #### 9.2.1 Stakeholder Validation **SyV-003**: System capabilities shall be validated against stakeholder requirements - User acceptance testing with business stakeholders - Functional validation with process owners - Integration validation with external service providers - Compliance validation with regulatory requirements ### 9.3 Acceptance Criteria #### 9.3.1 System Acceptance Criteria **SAC-001**: Performance requirements met under specified load conditions **SAC-002**: Security requirements validated through independent security assessment **SAC-003**: Compliance requirements certified through external audit **SAC-004**: Integration requirements validated through end-to-end testing **SAC-005**: Usability requirements validated through user acceptance testing --- ## 10. System Deployment and Operations ### 10.1 Deployment Requirements #### 10.1.1 Installation Requirements **SyD-001**: The system SHALL provide automated installation and configuration - MSI installer packages for WPF client application - Windows Service deployment for web service components - Database schema deployment and migration automation - Configuration management and validation #### 10.1.2 Update and Maintenance Requirements **SyD-002**: The system SHALL support in-place updates with minimal downtime - Rolling updates for web service components - Client application update mechanisms - Database schema migration with rollback support - Configuration preservation during updates ### 10.2 Operational Requirements #### 10.2.1 Monitoring Requirements **SyO-001**: The system SHALL provide comprehensive monitoring capabilities - Application performance monitoring (APM) - Database performance and health monitoring - External integration monitoring and alerting - User activity and security monitoring #### 10.2.2 Backup and Recovery Requirements **SyO-002**: The system SHALL provide robust backup and recovery procedures - Automated database backup with point-in-time recovery - Application configuration backup and restoration - Disaster recovery procedures and testing - Business continuity planning and execution --- ## 11. Traceability and Change Management ### 11.1 Requirements Traceability #### 11.1.1 Stakeholder to System Traceability All system requirements in this document are traceable to stakeholder requirements identified in StRS_Complete.md: - **User Management (SyR-013 to SyR-016)** ← **StR-046 to StR-049** - **CRM System (SyR-017 to SyR-020)** ← **StR-050 to StR-053** - **Financial System (SyR-021 to SyR-023)** ← **StR-054 to StR-056, StR-062** - **Helpdesk System (SyR-024 to SyR-026)** ← **StR-057 to StR-059** - **Project Management (SyR-027 to SyR-028)** ← **StR-063 to StR-064** - **Integration System (SyR-029 to SyR-031)** ← **StR-060 to StR-062** #### 11.1.2 Architecture to Implementation Traceability - **Client Architecture (SyR-001 to SyR-003)** → **src/centron/ components** - **Backend Architecture (SyR-002, SyR-049)** → **src/backend/ components** - **Web Service Architecture (SyR-052)** → **src/webservice/ components** - **Integration Architecture (SyR-053)** → **src/apis/ components** - **Shared Components (SyR-050)** → **src/shared/ components** ### 11.2 Change Management #### 11.2.1 Change Control Process **CM-001**: All system requirement changes must be evaluated for impact across: - Stakeholder requirement alignment and validation - Architectural consistency and integrity - Implementation complexity and timeline impact - Testing and validation requirement updates #### 11.2.2 Version Control and Documentation **CM-002**: System requirements documentation shall be maintained with: - Version control integration with source code - Change history and rationale documentation - Impact analysis and approval workflows - Stakeholder notification and communication --- ## 12. Conclusion This System Requirements Specification provides a comprehensive technical foundation for the Centron Enterprise Application, transforming stakeholder needs into detailed system capabilities and constraints. The requirements reflect the sophisticated multi-layered architecture with dual data access patterns, comprehensive external integrations, and enterprise-grade security and compliance features. ### 12.1 Key System Capabilities - **Multi-Modal Architecture**: Dual BL/WS implementation enabling both direct database and web service access - **Enterprise Integration**: 8 external API integrations providing comprehensive business process automation - **Modular Design**: Plugin-based architecture enabling flexible system extension and customization - **Comprehensive Security**: GDPR-compliant security framework with role-based access control - **German Market Focus**: Specialized compliance and localization for German enterprise requirements ### 12.2 Implementation Readiness The system requirements are directly traceable to the existing codebase architecture, ensuring implementation alignment and feasibility. The dual-pattern architecture (BL/WS Logic) provides flexibility for different deployment scenarios while maintaining consistent business logic implementation. ### 12.3 Quality Assurance The comprehensive verification and validation requirements ensure that all system capabilities meet stakeholder needs while maintaining enterprise-grade quality, security, and performance standards. --- **Document Control** - **Initial Version**: 1.0 - September 30, 2024 - **Review Cycle**: Monthly during development, quarterly during maintenance - **Next Review**: October 30, 2024 - **Approval Authority**: System Architecture Review Board - **Distribution**: Development teams, system architects, stakeholders **Related Documents** - StRS_Complete.md - Stakeholder Requirements Specification - SyRS_Summary.md - System Requirements Executive Summary - SyRS_Architecture.md - Detailed System Architecture - SyRS_Interfaces.md - System Interface Specifications - SyRS_API_Specification.yaml - REST API Specification - SyRS_Traceability.csv - Requirements Traceability Matrix