← Back to Projects

Supply Chain Project

Build Tamper-Proof Provenance Tracking

Learning Objectives

1. Model multi-party business processes on-chain
2. Implement role-based permissions
3. Create immutable audit trails
4. Design verification interfaces

Stakeholder Roles

Role	Permissions	Responsibilities
Admin	Full access	Deploy, manage roles
Producer	Create products	Register new items
Transporter	Update location	Move between stages
Warehouse	Store/release	Custody management
Retailer	Final sale	Sell to consumers
Consumer	Read only	Verify authenticity

Product Lifecycle

Data Model

struct Product {
    uint256 id;
    string name;
    string origin;
    uint256 createdAt;
    address currentOwner;
    ProductState state;
    string metadata;  // IPFS hash
}

struct HistoryEntry {
    uint256 timestamp;
    address actor;
    ProductState fromState;
    ProductState toState;
    string location;
    string notes;
}

Consumer Verification

1. Product has QR code linking to verification URL
2. Consumer scans with phone
3. Website queries blockchain for product history
4. Displays journey from origin to store

Cryptoeconomics Analysis

Question	Answer
PROBLEM	Verify product authenticity and journey
INCENTIVES	Brands protect reputation, consumers get guarantees
BENEFITS/COSTS	Tamper-proof records; onboarding complexity
FAILURE MODE	Garbage in = garbage out (first-mile problem)
DESIGN CHOICES	On-chain vs off-chain, permissioned vs public
ALTERNATIVES	Traditional barcodes, centralized databases

Implementation Checklist

• Deploy supply chain contract
• Configure roles for test accounts
• Create test products
• Test full product lifecycle
• Verify permission checks work
• Check history logging
• Build verification page
• Generate QR codes

Related Lessons

• L13: Smart Contract Platforms
• L15: Smart Contract Programming
• L27: Real-World Assets
• L28: Asset Tokenization

Resources

• OpenZeppelin AccessControl
• IBM Food Trust
• GS1 Standards