Xiaomi SU7's High Cohesion, Low Coupling Supplier Architecture Explained

The article opens with a widely circulated supplier diagram for the Xiaomi SU7, illustrating a highly cohesive and loosely coupled architecture. Xiaomi selected specialized suppliers for each critical function: CATL and BYD for battery cells, Bosch for the ABS braking system, and Huichuan Technology for the drive motor. This approach ensures each supplier delivers a specific capability while minimizing mutual dependencies.

High Cohesion and Low Coupling Defined

In software and enterprise architecture, high cohesion means a module's internal functions are tightly related, making it easier to understand and maintain. Low coupling means modules depend on each other as little as possible, allowing independent evolution without widespread impact. The author notes that these principles apply equally to enterprise architecture: a highly cohesive enterprise architecture groups related business processes and functions together, while low coupling ensures business units can interact flexibly yet remain relatively independent.

Enterprise Example: CRM System

An enterprise might centralize all customer-related processes in a CRM system (high cohesion) and connect it to finance, inventory, and other systems via APIs (low coupling). Upgrading or replacing the finance system then has minimal impact on the CRM or other systems.

Six Steps to Apply the Principles

Identify and partition modules: Recognize each module in the enterprise architecture and divide them by function, business process, or data usage, ensuring each has a clearly defined responsibility.

Design clear interfaces: Expose only necessary operations and data, hiding implementation details to reduce direct inter-module dependencies.

Minimize global variables: Avoid sharing global variables across modules; if unavoidable, manage access through services or interfaces.

Follow design principles and patterns: Apply Single Responsibility Principle, Open/Closed Principle, Law of Demeter, and similar patterns to boost cohesion and reduce coupling.

Refactor and optimize regularly: Periodically restructure the architecture to adapt to business changes while preserving high cohesion and low coupling.

Continuously monitor and evaluate: Track cohesion and coupling metrics, assess the impact of new requirements or technology shifts, and adjust accordingly.

The piece references a purported Xiaomi supplier chart and is part of Teacher Han's "One-Sentence Architecture" series, which includes articles on ISO 31000 risk management, TOGAF 10 governance checklists, bottom-up EA design pitfalls, EA organizational models, EA capabilities, EA definition and value, the Zachman framework, business capability identification, and process architecture layers.