Example of strategic design in DDD for an ERP system, focusing on the Order Management domain within the larger ERP context.

Let's take an example of strategic design in DDD for an ERP system, focusing on the Order Management domain within the larger ERP context.

Context:

Imagine a company that manufactures and sells electronic devices. The company has various business units, including manufacturing, sales, inventory management, and customer relations. The goal is to design a comprehensive ERP system to streamline the order management process.

Strategic Design Steps:

1. Identify Bounded Contexts:

   • Sales Context:
     • Subdomains: Order, Customer, Product, Pricing
   • Manufacturing Context:
     • Subdomains: Production, Inventory

2. Define Core Domains:

   • Order Management Domain:
     • Entities: Order, Order Line, Customer, Product
     • Value Objects: Address, Order Status
     • Aggregates: Order Aggregate (consisting of Order and Order Line)

3. Strategic Domain Events:

   • Order Placed: Triggered when a new order is placed.
   • Order Shipped: Triggered when an order is shipped from the warehouse.

4. Context Mapping:

   • Establish clear communication channels and integration points between the Sales and Manufacturing contexts.
   • Define shared Kernel to ensure consistency in shared concepts like Product and Customer.

5. Define Anti-Corruption Layer (ACL):

   • Implement an ACL to translate messages between the Sales and Manufacturing contexts, ensuring that the models from one context don't corrupt the models in the other.

6. Aggregate Root Design:

   • Order Aggregate:
     • Ensures consistency and encapsulation of order-related business rules.
     • Manages the order lifecycle, including order placement, modification, and shipment.

7. Strategic Repositories:

   • Implement repositories for key aggregates (e.g., OrderRepository) to manage the persistence of aggregates.

8. Value Objects for Immutability:

   • Use value objects for immutability, such as an Address value object for customer shipping information.

9. Policy Design:

   • Define pricing and discount policies as domain services to calculate the total order price based on the products and any applied discounts.

10. Continuous Refinement:

    • Regularly review and refine the strategic design based on evolving business requirements and feedback from stakeholders.

Below is a simplified Java pseudo-code representation of the strategic design steps outlined above for an ERP system, focusing on Order Management within the DDD context.

Step 1: Identify Bounded Contexts

// Sales Context
public class Order { /* ... */ }
public class Customer { /* ... */ }
public class Product { /* ... */ }
public class Pricing { /* ... */ }

// Manufacturing Context
public class Production { /* ... */ }
public class Inventory { /* ... */ }

Step 2: Define Core Domains

// Order Management Domain
public class Order {
    private OrderId orderId;
    private List<OrderLine> orderLines;
    private Customer customer;
    private OrderStatus status;
    // ... other attributes and methods
}

public class OrderLine {
    private Product product;
    private int quantity;
    private Money price;
    // ... other attributes and methods
}

public class Customer { /* ... */ }

public class Product { /* ... */ }

// Enums
public enum OrderStatus { PENDING, SHIPPED }

Step 3: Strategic Domain Events

// Events
public class OrderPlacedEvent { /* ... */ }
public class OrderShippedEvent { /* ... */ }

Step 4: Context Mapping

// Context Mapping
// Implement communication channels and integration points between Sales and Manufacturing contexts

Step 5: Define Anti-Corruption Layer (ACL)

// Anti-Corruption Layer
public class SalesToManufacturingTranslator {
    public ManufacturingOrder translate(Order order) {
        // Translate Order to ManufacturingOrder
    }
}

public class ManufacturingToSalesTranslator {
    public Order translate(ManufacturingOrder manufacturingOrder) {
        // Translate ManufacturingOrder to Order
    }
}

Step 6: Aggregate Root Design

// Aggregate Root
public class OrderAggregate {
    private Order order;
    // ... other attributes and methods

    public void placeOrder(OrderPlacedEvent event) {
        // Handle order placement logic
    }

    public void shipOrder(OrderShippedEvent event) {
        // Handle order shipment logic
    }
}

Step 7: Strategic Repositories

// Repository
public interface OrderRepository {
    Order getById(OrderId orderId);
    void save(Order order);
}

Step 8: Value Objects for Immutability

// Value Object
public class Address {
    private String street;
    private String city;
    private String zipCode;
    // ... other attributes and methods
}

Step 9: Policy Design

// Domain Service
public class PricingService {
    public Money calculateTotalPrice(Order order) {
        // Calculate total price based on order and pricing policies
    }
}

Step 10: Continuous Refinement

// Regularly review and refine the design based on evolving requirements

Please note that this pseudo-code is simplified for illustration purposes. In a real-world scenario, you would need to implement the methods, handle exceptions, and consider additional aspects like persistence, validation, and error handling.