10. MVP Migration Path

Overview

Path from MVP (4 contexts, desktop) to full version (web-based, distributed).

Current MVP Architecture

4 Bounded Contexts:
├── Configuration (file loading)
├── Retrofit Workflow (simulation)
├── Railway Infrastructure (track management)
└── External Trains (arrivals)

Integration: Direct calls + Event bus
Storage: File-based (JSON/CSV)
UI: CLI + Matplotlib
Deployment: Desktop

Full Version Target

Multiple Contexts (TBD):
├── Configuration
├── Simulation Engine
├── Railway Infrastructure
├── Train Operations
├── Workshop Management
├── Resource Management
└── Analytics

Integration: Event-driven (async messaging)
Storage: Database + Event Store
UI: Web interface (interactive)
Deployment: Cloud-ready

Migration Phases

Phase 1: Event-Driven Architecture

Current: Direct method calls + simple event bus

Target: Full event-driven with async messaging

Changes: - Replace direct calls with domain events - Add event store for persistence - Implement saga pattern for workflows

Effort: 2-3 weeks

Phase 2: Database Integration

Current: File-based configuration

Target: Database storage with repository pattern

Changes: - Add repository interfaces - Implement database repositories - Migrate file loading to database queries

Effort: 1-2 weeks

Phase 3: Web Interface

Current: CLI + Matplotlib charts

Target: Web UI with interactive visualization

Changes: - Add REST API layer - Implement web frontend - Real-time simulation updates

Effort: 4-6 weeks

Phase 4: Context Refinement

Current: 4 contexts

Target: More specialized contexts

Changes: - Split Retrofit Workflow into smaller contexts - Add new contexts as needed - Refine boundaries based on learnings

Effort: 2-3 weeks

Technical Debt to Address

High Priority

1. SimPy Abstraction
2. Current: Direct SimPy usage in coordinators
3. Target: Full abstraction layer

4. Effort: 3 days

5. Service Interfaces

6. Current: Concrete implementations
7. Target: Interface-based design
8. Effort: 5 days

Medium Priority

1. Repository Pattern
2. Current: Direct file access
3. Target: Repository interfaces

4. Effort: 3 days

5. Error Handling

6. Current: Basic exception handling
7. Target: Comprehensive error strategy
8. Effort: 2 days

Compatibility Strategy

Backward Compatibility

• Keep file-based configuration support
• Maintain CLI interface alongside web UI
• Support both local and cloud deployment

Data Migration

• Provide migration scripts for file → database
• Support hybrid mode during transition
• Maintain data format compatibility

Risk Mitigation

Risk	Mitigation
Breaking changes	Maintain MVP as stable branch
Performance degradation	Benchmark before/after
Complexity increase	Incremental migration
Team learning curve	Training and documentation

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