TOGAF (The Open Group Architecture Framework) organizes enterprise architecture into four interrelated domains. These domains provide a structured way to analyze, design, and implement systems that align with business goals.

🔍 The Four Architecture Domains (Explained in Detail)

1. Business Architecture

This domain defines:

• The organizational structure
• Business processes
• Capabilities, functions, and roles
• Strategic goals and objectives

It answers:
👉 What does the business do? Who does it? Why does it matter?

2. Data Architecture

This domain focuses on:

• Data models (conceptual, logical, physical)
• Data flows and data governance
• Data storage, integration, and security

It answers:
👉 What data is needed? Where is it stored? How is it accessed and secured?

3. Application Architecture

This domain defines:

• The software applications used in the enterprise
• Interactions between applications
• Interfaces and integration patterns

It answers:
👉 What applications support the business? How do they interact?

4. Technology Architecture

This domain includes:

• Infrastructure (servers, networks, cloud platforms)
• Middleware, operating systems, and technical standards
• Security, performance, and scalability

It answers:
👉 What technology supports the applications and data?

🧠 Real-World Example: Smart City Transportation System

Let’s say a city government is building a Smart Transportation System to reduce traffic congestion and improve commuter experience.

🔹 Business Architecture

• Goal: Reduce average commute time by 20% in 2 years.
• Stakeholders: City planners, commuters, traffic police, public transport authorities.
• Processes: Route planning, traffic monitoring, public transport scheduling.

🔹 Data Architecture

• Data Sources: GPS data from buses, traffic sensors, commuter feedback, weather data.
• Data Models: Real-time traffic flow, historical congestion patterns.
• Governance: Data privacy policies, open data standards for public access.

🔹 Application Architecture

• Apps: Mobile app for commuters, dashboard for traffic control center, APIs for third-party developers.
• Integration: Real-time data feeds from IoT sensors, integration with Google Maps and public transport APIs.

🔹 Technology Architecture

• Infrastructure: Cloud-based platform (e.g., AWS or Azure), 5G connectivity, edge computing for real-time processing.
• Security: End-to-end encryption, role-based access control.
• Scalability: Designed to support millions of data points per day.

🖼 Visual Diagram

Here’s a visual representation of how these domains stack and interact:

📝 Summary

The four architecture domains in TOGAF—Business, Data, Application, and Technology—offer a comprehensive framework for aligning IT with business strategy. Whether you’re building a smart city, modernizing a bank, or transforming healthcare, these domains help ensure that every layer of your enterprise is working in harmony.