Domain-Driven Design: Tackling Complexity in the Heart of Software Hardcover – Aug 20 2003
|New from||Used from|
Frequently Bought Together
Customers Who Bought This Item Also Bought
No Kindle device required. Download one of the Free Kindle apps to start reading Kindle books on your smartphone, tablet, and computer.
Getting the download link through email is temporarily not available. Please check back later.
To get the free app, enter your mobile phone number.
From the Inside Flap
Leading software designers have recognized domain modeling and design as critical topics for at least twenty years, yet surprisingly little has been written about what needs to be done or how to do it. Although it has never been clearly formulated, a philosophy has developed as an undercurrent in the object community, which I call "domain-driven design".I have spent the past decade focused on developing complex systems in several business and technical domains. I've tried best practices in design and development process as they have emerged from the leaders in the object-oriented development community. Some of my projects were very successful; a few failed. A feature common to the successes was a rich domain model that evolved through iterations of design and became part of the fabric of the project.This book provides a framework for making design decisions and a technical vocabulary for discussing domain design. It is a synthesis of widely accepted best practices along with my own insights and experiences. Projects facing complex domains can use this framework to approach domain-driven design systematically.Contrasting Three ProjectsThree projects stand out in my memory as vivid examples of the dramatic effect domain design practice has on development results. Although all three delivered useful software, only one achieved its ambitious objectives and delivered complex software that continued to evolve to meet ongoing needs of the organization.I watched one project get out of the gate fast with a useful, simple web-based trading system. Developers were flying by the seat of their pants, but simple software can be written with little attention to design. As a result of this initial success, expectations for future development were sky-high. It was at this point that I was approached to work on the second version. When I took a close look, I saw that they lacked a domain model, or even a common language on the project, and were saddled with an unstructured design. So when the project leaders did not agree with my assessment, I declined the job. A year later, they found themselves bogged down and unable to deliver a second version. Although their use of technology was not exemplary, it was the business logic that overcame them. Their first release had ossified prematurely into a high-maintenance legacy.Lifting this ceiling on complexity calls for a more serious approach to the design of domain logic. Early in my career, I was fortunate to end up on a project that did emphasize domain design. This project, in a domain at least as complex as the one above, also started with a modest initial success, delivering a simple application for institutional traders. But this delivery was followed up with successive accelerations of development. Each successive iteration opened exciting new options for integration and elaboration of functionality. The team way able to respond to the needs of the traders with flexibility and expanding capability. This upward trajectory was directly attributable to an incisive domain model, repeatedly refined and expressed in code. As the team gained new insight into the domain, the model deepened. The quality of communication improved among developers and between developers and domain experts, and the design, far from imposing an ever-heavier maintenance burden, became easier to modify and extend.Unfortunately, not all projects that start with this intention manage to arrive at this virtuous cycle. One project I joined started with lofty aspirations to build a global enterprise system based on a domain model, but finally had a disappointing result. The team had good tools, a good understanding of the business and gave serious attention to modeling. But a separation of developer roles led to a disconnect between the model and implementation, so the design did not reflect the deep analysis that was going on. In any case, the design of detailed business objects was not rigorous enough to support combining them in elaborate applications. Repeated iteration produced no improvement in the code, due to uneven skill-level among developers with no clear understanding of the particular kind of rigor needed. As months rolled by, development work became mired in complexity and the team lost its cohesive vision of the system. After years of effort, the project did produce modest, useful software, but had given up the early ambitions along with the model focus.Of course many things can put a project off course, bureaucracy, unclear objectives, lack of resources, to name a few, but it is the approach to design that largely determines how complex software can become. When complexity gets out of hand, the software can no longer be understood well enough to be easily changed or extended. By contrast, a good design can make opportunities out of those complex features.Some of these design factors are technological, and a great deal of effort has gone into the design of networks, databases, and other technical dimension of software. Books have been written about how to solve these problems. Developers have cultivated their skills.Yet the most significant complexity of many applications is not technical. It is in the domain itself, the activity or business of the user. When this domain complexity is not dealt with in the design, it won't matter that the infrastructural technology is well-conceived. A successful design must systematically deal with this central aspect of the software.The premise of this book is that
- For most software projects, the primary focus should be on the domain and domain logic.
- Complex domain designs should be based on a model.
- Domain-driven design is a way of thinking and a set of priorities, aimed at accelerating software projects that have to deal with complicated domains. To accomplish that goal, this book presents an extensive set of design practices, techniques and principles.
- Iterative development. The practice of iterative development has been advocated and practiced for decades, and is a corner stone of the Agile development methods. There are many good discussions in the literature of Agile development and Extreme Programming, among them, Cockburn1998 and Beck 1999.
- A close relationship between developers and domain experts. Domain-driven design crunches a huge amount of knowledge into a model that reflects deep insight into the domain and a focus on the key concepts. This is a collaboration between those who know the domain and those who know how to build software. Because it is iterative, this collaboration must continue throughout the project's life.
From the Back Cover
“Eric Evans has written a fantastic book on how you can make the design of your software match your mental model of the problem domain you are addressing.
“His book is very compatible with XP. It is not about drawing pictures of a domain; it is about how you think of it, the language you use to talk about it, and how you organize your software to reflect your improving understanding of it. Eric thinks that learning about your problem domain is as likely to happen at the end of your project as at the beginning, and so refactoring is a big part of his technique.
“The book is a fun read. Eric has lots of interesting stories, and he has a way with words. I see this book as essential reading for software developers—it is a future classic.”—Ralph Johnson, author of Design Patterns
“If you don’t think you are getting value from your investment in object-oriented programming, this book will tell you what you’ve forgotten to do.
“Eric Evans convincingly argues for the importance of domain modeling as the central focus of development and provides a solid framework and set of techniques for accomplishing it. This is timeless wisdom, and will hold up long after the methodologies du jour have gone out of fashion.”—Dave Collins, author of Designing Object-Oriented User Interfaces
“Eric weaves real-world experience modeling—and building—business applications into a practical, useful book. Written from the perspective of a trusted practitioner, Eric’s descriptions of ubiquitous language, the benefits of sharing models with users, object life-cycle management, logical and physical application structuring, and the process and results of deep refactoring are major contributions to our field.”—Luke Hohmann, author of Beyond Software Architecture
"This book belongs on the shelf of every thoughtful software developer."
"What Eric has managed to capture is a part of the design process that experienced object designers have always used, but that we have been singularly unsuccessful as a group in conveying to the rest of the industry. We've given away bits and pieces of this knowledge...but we've never organized and systematized the principles of building domain logic. This book is important."
--Kyle Brown, author of Enterprise Java™ Programming with IBM® WebSphere®
The software development community widely acknowledges that domain modeling is central to software design. Through domain models, software developers are able to express rich functionality and translate it into a software implementation that truly serves the needs of its users. But despite its obvious importance, there are few practical resources that explain how to incorporate effective domain modeling into the software development process.
Domain-Driven Design fills that need. This is not a book about specific technologies. It offers readers a systematic approach to domain-driven design, presenting an extensive set of design best practices, experience-based techniques, and fundamental principles that facilitate the development of software projects facing complex domains. Intertwining design and development practice, this book incorporates numerous examples based on actual projects to illustrate the application of domain-driven design to real-world software development.
Readers learn how to use a domain model to make a complex development effort more focused and dynamic. A core of best practices and standard patterns provides a common language for the development team. A shift in emphasis--refactoring not just the code but the model underlying the code--in combination with the frequent iterations of Agile development leads to deeper insight into domains and enhanced communication between domain expert and programmer. Domain-Driven Design then builds on this foundation, and addresses modeling and design for complex systems and larger organizations.Specific topics covered include:
- Getting all team members to speak the same language
- Connecting model and implementation more deeply
- Sharpening key distinctions in a model
- Managing the lifecycle of a domain object
- Writing domain code that is safe to combine in elaborate ways
- Making complex code obvious and predictable
- Formulating a domain vision statement
- Distilling the core of a complex domain
- Digging out implicit concepts needed in the model
- Applying analysis patterns
- Relating design patterns to the model
- Maintaining model integrity in a large system
- Dealing with coexisting models on the same project
- Organizing systems with large-scale structures
- Recognizing and responding to modeling breakthroughs
With this book in hand, object-oriented developers, system analysts, and designers will have the guidance they need to organize and focus their work, create rich and useful domain models, and leverage those models into quality, long-lasting software implementations.
See all Product Description
What Other Items Do Customers Buy After Viewing This Item?
Top Customer Reviews
I once led a young software team and tried to convey the need for and essence of these skills to them, but I didnt have the right words and terms to do it for their level of experience. I wish this book had been available to me then because I think it would have made a real difference for that team.
5 stars for a technical book indicates to me a book of profound quality that really breaks through with penetrating insights -- The kind of book that makes me think, "Wow, this book has really brought my development practice into a renewed, sharper focus." It doesn't necessarily have to provide radically new material, but it does have to package whatever material it contains in a way that causes the gears in my head to shift around and reorganize themselves. Design Patterns is such a book. XP Explained is such a book. I don't think this one qualifies.
Some good points: The author makes a good case for agile development/extreme programming (close relationship with the customer, unit tests, refactoring...). He seems to believe there may be a tendency to over-emphasize the importance of code and to neglect design in such practices, which may or may not be true in industry at large. But in any case, his major thesis is that it is also important to consider the overall domain model and how well-aligned it is to the goals of the business. He proposes developing a common ("ubiqitous") language between developers and business users, and to unify the various traditional views of a software system (requirements, analysis model, design model, etc..) into one. The advice is quite wholesome and will hopefully promote bringing some harmony between the agile camp and the adherents of high-ceremony approaches such as RUP and CMM.
Some bad points: The book is rather wordy, and a lot of common-sense ideas are repeated at length. I don't feel that the patterns in the book are much more than re-statements of basic principles of OO design.Read more ›
Why five stars? Because this book peels off the layers of what is wrong with development, discarding them and replacing them with alternatives that promote communications among all stakeholders, placing design into its proper context, and provides the glue that binds subject matter experts from business and technology domains into a cohesive team using the same language and pursuing the same goals. On the surface this seems like common sense, but in practice, it is rarely done. Indeed, the lack of the ingredients given in this book on most projects is the reason why so many projects fail or are cancelled, and why there exists today a real disconnect between IT and the business. Following this book, implementing the practices, and managing to them will make a world of difference in the success rate of any organization, large or small.
I like the copious examples to illustrate the technical concepts, and especially chapters 9 (Making Implicit Concepts Explicit) and 14 (Maintaining Model Integrity) because these are two areas in design that I've observed to be potential failure points - the first because too often wrong assumptions are made and locked in, and the second because models sometimes take on a life of their own and morph into unintended things.
This book emphasizes a number of critical success factors, including knowledge, communication, control and vision.Read more ›
Most recent customer reviews
Its a bible for developers who wants to understand design patterns. One of the all time best book.Published 10 months ago by Boby
If you are the kind of developper who not only want to do stuff, but do them right, then this is the book for you. Read morePublished on July 28 2009 by Laurent Bourgault-Roy
I bought this book after seeing Eric speak at XPAU in Calgary (2004). He gave an interesting talk and so I took a flyer on his book. Read morePublished on Oct. 11 2005 by Amazon Customer
I read this book in its draft form on a cross-country flight and was just blown away by it, enough so that I bought a bound version to make it easier to carry around and... Read morePublished on July 15 2004 by James Frohnhofer
This book sets the expectations for grandiose and profound insights on software engineering, but it really failed to deliver. Read morePublished on June 27 2004 by Alex Iskold
This book answers the question of how you tie in cookbooks like the GoF book or Fowler's Enterprise Patterns book with the Wirfs-Brock book on designing systems. Read morePublished on June 6 2004 by Lars Bergstrom
This book is truly an original work. It shows that the author took his time in writing and editing this book - it is not slapped together like so many technical books these days. Read morePublished on May 29 2004
Look for similar items by category
- Books > Computers & Technology > Computer Science > Software Engineering > Design Tools & Techniques
- Books > Computers & Technology > Computer Science > Systems Analysis & Design
- Books > Computers & Technology > Programming > Software Design, Testing & Engineering > Object-Oriented Design
- Books > Computers & Technology > Programming > Software Design, Testing & Engineering > Software Development
- Books > Computers & Technology > Software
- Books > Qualifying Textbooks - Fall 2007 > Computers & Internet
- Books > Textbooks > Computer Science & Information Systems > Computer Science
- Books > Textbooks > Computer Science & Information Systems > Object-Oriented Software Design
- Books > Textbooks > Computer Science & Information Systems > Programming Languages
- Books > Textbooks > Computer Science & Information Systems > Software Design & Engineering