# Chatbot Architecture Trade-off Analysis

## Cost Analysis
| Aspect | Multi-tenant | Single-tenant |
|--------|-------------|---------------|
| Infrastructure | Lower - Shared resources reduce cloud costs by 40-60% | Higher - Each tenant requires dedicated resources |
| Maintenance | Lower - Single codebase and deployment | Higher - Multiple deployments and environments |
| Operations | Lower - Centralized monitoring and management | Higher - Separate monitoring per tenant |
| Database | Lower - Shared instances with proper indexing | Higher - Dedicated instances per tenant |
| Estimated Monthly Cost* | $5,000-8,000 per 100 tenants | $800-1,200 per tenant |

*Based on typical cloud provider pricing for similar architectures

## Implementation Effort
| Task | Multi-tenant | Single-tenant |
|------|-------------|---------------|
| Initial Setup | 60-80 mandays | 30-40 mandays |
| Tenant Isolation | 40-50 mandays | 10-15 mandays |
| Security Implementation | 30-40 mandays | 15-20 mandays |
| Database Design | 25-30 mandays | 10-15 mandays |
| Testing & QA | 40-50 mandays | 20-25 mandays |
| Total Estimate | 195-250 mandays | 85-115 mandays |

## Resource Sharing
| Resource | Multi-tenant | Single-tenant |
|----------|-------------|---------------|
| Compute | High sharing (75-85% utilization) | Low sharing (30-40% utilization) |
| Memory | Efficient pooling | Dedicated with overhead |
| Storage | Optimized shared storage | Separate storage per tenant |
| Network | Shared bandwidth | Dedicated bandwidth |
| Cache | Shared with tenant isolation | Dedicated per tenant |

## Stability
| Factor | Multi-tenant | Single-tenant |
|--------|-------------|---------------|
| Fault Isolation | Lower - Issues can affect all tenants | Higher - Issues isolated to single tenant |
| Recovery Time | Slower - Complex tenant data recovery | Faster - Straightforward recovery |
| Maintenance Impact | Higher risk during updates | Lower risk, staged updates possible |
| Performance Stability | Variable due to tenant interference | Consistent and predictable |
| Estimated Uptime | 99.5-99.9% | 99.9-99.99% |

## Scalability
| Aspect | Multi-tenant | Single-tenant |
|--------|-------------|---------------|
| Horizontal Scaling | Complex but cost-effective | Simple but expensive |
| Vertical Scaling | Limited by tenant interference | Flexible per tenant needs |
| Load Balancing | Complex tenant-aware routing | Simple direct routing |
| Growth Capacity | High with proper architecture | Limited by infrastructure |
| Cost per New Tenant | Very low marginal cost | Linear cost increase |

## Long-Term Risk
| Risk Factor | Multi-tenant | Single-tenant |
|------------|-------------|---------------|
| Technology Migration | Complex - All tenants affected | Simple - Can migrate gradually |
| Vendor Lock-in | Higher risk - Shared infrastructure | Lower risk - Independent systems |
| Security Compliance | Complex - Shared responsibility | Simple - Isolated compliance |
| Architecture Changes | High impact - System-wide changes | Low impact - Incremental changes |
| Data Privacy Laws | Complex adaptation needed | Simpler to adapt per region |
| Future Maintenance | Increases with tenant count | Linear with tenant count |

## Deployment Strategy
| Aspect | Multi-tenant | Single-tenant |
|--------|-------------|---------------|
| Release Management | Complex orchestration across shared environment | Simple independent deployments |
| Rollback Process | High risk, affects all tenants | Low risk, tenant-specific |
| Blue-Green Deployment | Complex tenant data migration | Straightforward environment switch |
| Canary Releases | Requires tenant-aware traffic routing | Simple percentage-based routing |
| Downtime Impact | All tenants affected | Only specific tenant affected |
| Environment Costs | Lower - Shared staging/UAT | Higher - Separate environments needed |
| Backup Strategy | Complex tenant-aware backups | Simple full-system backups |
| Recovery Time Objective | 2-4 hours typically | 30-60 minutes typically |