Proposal.md Format

Document structure

# Add Barcode Scanning for Warehouse

## Why

### Problem Statement
Warehouse staff currently search products manually during receiving.
Average time to receive one item is 45 seconds, 30 seconds of which
is spent finding the product in the system.

### Business Impact
- Slow receiving (200 items/day = 100 minutes of searching)
- High error rate (3% misentered products)
- Employee frustration

### Success Metrics
- Reduce receive time per item to 15 seconds
- Reduce error rate below 0.5%
- Warehouse NPS > 8

## What Changes

### Scope
1. **Mobile interface for scanning**
   - PWA app for Android/iOS
   - Camera API integration
   - Offline-first architecture

2. **Backend changes**
   - Endpoint for lookup by EAN
   - Barcode validation
   - Scan logging

3. **UI changes**
   - New "Scan" field on the receipt
   - Audio/visual feedback

### Out of Scope
- RFID scanning (Phase 2)
- Automatic purchase orders for low stock
- External warehouse integrations

## Impact Analysis

### Affected Entities
| Entity | Change |
|--------|--------|
| StockReceipt | New fields `scannedAt`, `scannedById` |
| StockReceiptItem | New field `scannedEan` |
| Product | No change (EAN already exists) |

### Affected Modules
- Warehouse Management (primary)
- Product Base (secondary - EAN lookup)

### Dependencies
- Products must have EAN filled
- Mobile devices with camera
- HTTPS for camera API

### Risks
| Risk | Probability | Impact | Mitigation |
|------|-------------|--------|-----------|
| Unreadable barcodes | Medium | Low | Manual entry fallback |
| Offline issues | Low | Medium | Local storage + sync |
| Performance on older devices | Medium | Medium | Minimum requirements |

## Effort Estimation

| Component | Hours |
|-----------|-------|
| Backend API | 8 |
| PWA application | 24 |
| UI integration | 8 |
| Testing | 8 |
| Documentation | 4 |
| **Total** | **52** |

## Approval

| Role | Name | Status | Date |
|------|------|--------|------|
| Product Owner | Marie R. | ✅ Approved | 2025-02-10 |
| Tech Lead | Jan V. | ✅ Approved | 2025-02-11 |
| Architect | Petr K. | ✅ Approved | 2025-02-11 |

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Review checklist

• [ ] Proposal clearly explains WHY (not just WHAT)
• [ ] Impact analysis is complete
• [ ] Effort estimate is realistic
• [ ] Risks are identified with mitigation

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