Romano Roth & Dietmar Wettach
A practical guide to value-driven enterprise architecture
Get enterprise architecture out of the ivory tower.
From USD 12.99.
They were promoted for the decision it made possible.
There is a pattern to how EA practices fail. The models get more detailed, the governance gets heavier, and the people who make the real decisions stop showing up. The architecture is correct, and nobody uses it.
Lean Enterprise Architecture treats EA as a leadership discipline that connects strategy with execution and business with technology. It applies one rule throughout: start small, deliver value early, and expand only where the organization genuinely benefits.
You will learn to build capability maps, evaluate an application landscape, design a target architecture, and defend an architecture decision in front of a portfolio board. It covers the methods in daily use, TOGAF, Zachman, ArchiMate, BPMN, DMN, UML and C4, alongside governance, portfolio management, IT controlling, cloud-native platforms, FinOps and AI.
It also covers the half that decides whether an architecture survives an audit: the Three Lines of Defense applied to architecture, digital sovereignty under DORA, NIS2, GDPR and the Swiss DSG, and the four risk tiers of the EU AI Act.
The point is to move you from executing architecture decisions to shaping them.
Why now
AI was in your organization months before the steering committee held its first meeting.
Teams adopt AI tools long before a strategy exists. Someone has to know which models run on which data, and who answers for what they produce. That is an architecture question, and it needs an answer in weeks, which is the pace the lean approach of this book is built for.
AI is only as good as the data it reads. Chapter 12 covers what AI workloads demand of the data architecture: vector databases, feature stores and data lineage.
Part VI shows how models and inference endpoints extend the architecture metamodel, and which AI governance model fits which organization. It argues why compliance sign-off and audit trails stay with people, and it covers the four risk tiers of the EU AI Act.
Written for the book
This book presents Enterprise Architecture as a practical tool instead of a theory. It helps people understand organizations and shape digital change.
Students will find conceptual clarity, practitioners will discover concrete methods, and leaders will gain a unifying language that bridges boardroom vision with engineering reality.
The shape of it
Each chapter stands on its own, so you can read the book end to end or go straight to the topic you need.
Establishes the conceptual foundation for enterprise architecture, covering definitions, roles, communication, lean principles, and maturity assessment.
Connects enterprise architecture to organizational change, covering transformation planning and change management.
Explores the six core architecture domains: business, capability, information, application landscape, data, and integration.
Covers the governance mechanisms that make architecture decisions stick: compliance frameworks, portfolio management, and IT controlling.
Enterprise architecture does not happen in the abstract. It requires a shared language, a structured process, and the right instruments to turn strategic intent into operational reality.
Addresses the technology dimension of enterprise architecture, from strategy through operations and patterns, including AI fundamentals and practice.
Synthesizes the key themes and provides forward-looking guidance for enterprise architects.
Lecture companion
The book was written as the lecture companion for the CAS Enterprise Architecture at the Lucerne University of Applied Sciences and Arts, and built to stay on your desk afterwards. 28 of the 32 chapters map to a CAS module. The remaining 4 add material the program does not cover.
Written by
Romano approaches enterprise architecture from the frontier, Dietmar from the inside. Neither could have written this book alone.
