Simple Architectures for Complex Enterprises (PRO-best Practices) (Best Practices (Microsoft)) (Paperback)

~ (Author)
Key Phrases: enterprise partitions, software fortresses, appointment booking, Rubik's Cube, Mathematics of Complexity, Enterprise Architecture Today (more...)

Editorial Reviews

Product Description

Dismantle the overwhelming complexity in your IT projects with strategies and real-world examples from a leading expert on enterprise architecture. This guide describes best practices for creating an efficient IT organization that consistently delivers on time, on budget, and in line with business needs.

IT systems have become too complex and too expensive. Complexity can create delays, cost overruns, and outcomes that do not meet business requirements. The resulting losses can impact your entire company. This guide demonstrates that, contrary to popular belief, complex problems demand simple solutions. The author believes that 50 percent of the complexity of a typical IT project can and should be eliminated and he shows you how to do it.

You ll learn a model for understanding complexity, the three tenets of complexity control, and how to apply specific techniques such as checking architectures for validity. Find out how the author s methodology could have saved a real-world IT project that went off track, and ways to implement his solutions in a variety of situations.

Key Book Benefits:

 Presents a model for understanding IT and enterprise complexity  Provides practical solutions for controlling complexity, and shows how they can be applied in a variety of situations  Features a methodology for checking architectures for validity  Explains how to apply simplification algorithms to software systems  Includes a real-world case study that demonstrates how the author s solutions could have saved an actual IT project that went wrong

About the Author

Roger Sessions is a recognized expert in enterprise architecture. He serves on the Board of Directors of the International Association of Software Architects (IASA), is Editor-in-Chief of IASA s Perspectives Journal, and is a Microsoft MVP in enterprise architecture. He has written six books, including Software Fortresses: Modeling Enterprise Architectures, and many articles. He has been a keynote speaker on the topic of enterprise architecture for dozens of events in more than 30 countries. He is the Chief Technology Officer of ObjectWatch.

Product Details

• Paperback: 208 pages
• Publisher: Microsoft Press (May 19, 2008)
• Language: English
• ISBN-10: 0735625786
• ISBN-13: 978-0735625785
• Product Dimensions: 8.9 x 7.3 x 0.8 inches
• Shipping Weight: 13.6 ounces (View shipping rates and policies)
• Average Customer Review: 3.5 out of 5 stars  See all reviews (8 customer reviews)
• Amazon.com Sales Rank: #71,817 in Books (See Bestsellers in Books)

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Customer Reviews

Most Helpful Customer Reviews

10 of 11 people found the following review helpful:

5.0 out of 5 stars Architectural Common Sense, July 12, 2008

By	Professional Computer Geek - See all my reviews

I have managed to talk to quite a few good software/enterprise architects over the years. When I do, the issues that we often talk about most are simplicity of design and how to manage complexity. In general, understanding that the management of complexity is the fundamental task of architecture is what defines a good architect. This book indicates that Roger really gets this issue. He also seems to get the business alignment issues that are sometimes lacking from architecture texts.

From Roger's advice on partitioning a solution to his advice on implementing a system using an incremental approach everything here is sound and well articulated. This book is a short read but almost definitely worth your time if you are building anything in software from an enterprise down. Much of the principles he professes are the same principles that are important in regular software architecture. Components and object oriented design are merely methods of figuring out internal equivalence classes and appropriately partitioning solutions. Iterative development and some of the new agile principles are based on the same idea he advocates for the enterprise, incremental delivery.

If for nothing else, this book is useful because Sessions is very successful in mathematically proving that many of his ideas should work. Most texts advocating incremental methodologies or problem decomposition can sound evangelical. This book does not.

Overall, SIP sounds like it is a very good foundation for a company's enterprise architecture.

That said, I am sure my advice would mean more if I did enterprise architecture. I hope that it is merely enough to say this.. I am in software development. I have helped provide or provided the technical architecure on quite a few projects. I feel that in general Roger has the core concerns nailed with his book.

5 of 5 people found the following review helpful:

4.0 out of 5 stars Not 100% applicable, January 30, 2009

By	Aaron Seet "icelava" (Singapore) - See all my reviews (REAL NAME)

The general approach to any grand IT problem is to break it down to smaller manageable pieces. Pieces that our pathetically puny brains can contain and work on at a time. Any decent software developer would have known that. And yet, we still continue to produce massive, monstrous, monolithic code that is a complete beast to interpret, comprehend, and modify. In other words, a mesh of _unmanageable_complexity_. There is without a doubt such technical misshaping contribute significantly to the schedule and budget overrun in way too many large projects, and ultimate failure.

But what am I talking about? This book is not about software applications. As an enterprise architect, Author Roger Sessions takes us up several floors to show us where he believes all these complexity evil germinates - the failure to control the complexity of IT inter-system communication across the organisation. He writes this volume to explain the problem of complexity can be illustrated via mathematical models, and purports that the application these mathematical exercises and further concepts of organisation will help divide the enterprise into simple easy pieces.

_That_ is a rather mighty claim. Is this for real?

Roger Sessions starts out strong. He begins mentioning existing methodologies and frameworks used to organise architectures in the present industry and highlights rather glaringly the missing piece in all of them - the deliberate effort to ensure the output of the work is simple. The next two chapters quickly move on present some simple real-world scenarios (like a rubik's cube, chess games, team and store organisation, etc) and then the math behind them, on how dividing them - partitioning - into smaller pieces of a bigger whole helps to solve the problem they present in a much less troublesome manner. The mathematics introduced is simple enough to understand and convincing. But somehow the lessons would be re-taught every now and then; I found the repeated explanations to be redundant and approaching incessant. It is almost as though the author fears the readers may not be convinced enough and needed reminders. Or there is the assumption the intended audience largely failed elementary math in school.

As convincing as the principles behind the math are, my disappointment set in when the transition from pure math theory into real-world business modeling began. If you think it sounded too good to be true that real-world architecture can be tackled with simplistic mathematical models, well, it is. Even Roger Sessions himself admits that real-world circumstances is in fact, not that simple. The problem with the absolute black-white nature of mathematical theory is it excludes many (grey) inter-object relationships or channels that real-world organisations would inherently possess; they cannot be blindly ignored. Take for example, the Five Laws of Partitions

First Law of Partitions - Partitions must be true partitions.
Second Law of Partitions - Partition definitions must be appropriate to the problem at hand.
Third Law of Partitions - The number of subsets in a partition must be appropriate.
Fourth Law of Partitions - The size of the subsets in a partition must be roughly equal.
Fifth Law of Partitions - The interactions between subsets in the partitions must be minimal and well defined.

With such vague "laws" I predict a chasm of opportunities for unending subjective debates over what "appropriate", "equal size", "minimal", or "well defined" can truly mean when it comes to discussing how to partition a real organisation into smaller units. Therefore the fourth chapter's technique of Autonomous Business Capabilities (ABC) did not resonate well with me as I pondered how this applies to real departments and divisions. It is just not that simple. However, Roger Sessions' intention is squarely - and rightfully - focused on breaking things down simple enough to benefit the _business_.

On a side note, I found his deliberate avoidance to discuss application systems somewhat isolative. As a software developer, I find many of the principles he puts forth are directly applicable, and even taught, at the level of software architecture and design. Like it or not, the lifeblood of any enterprise is the myriad of software applications; keeping their design simple is as important as keeping the enterprise simple. In fact the SIP (Simple Iterative Partitions) process he recommends resembles Agile practices a lot. Somehow, I get the feeling Roger Sessions has forgotten failure in IT projects is contributed by many things happening at all levels, not just enterprise architecture alone.

It is difficult to label this book as truly seminal; due to the various falling pieces, I cannot feel the utter greatness. But don't be deceived - it has been a good _mind-stretching_ exercise (not mind-blowing). Roger Sessions has presented some eye-opening ideas that allowed me to gain new light in this argument for simplicity. His message is clear - there not enough people consciously considering simplifying things they work on; and accomplishing things by smaller projects of iterative sequence. I wholeheartedly agree on this. If the word "simplicity" never flashed across your mind (are you reading this, CIOs, CTOs, and architects???) while you were thinking through architecture or design, you need this book to yaw yourself in the right direction.

OVERALL RATING: 7/10
GOOD: Refreshing perspective; interesting model & approach for architecture; gets the point across
BAD: Repetitive; model not 100% mapped to real world; concept not 100% new; the IT problem spans across more than one area

5 of 6 people found the following review helpful:

2.0 out of 5 stars Where's the Beef?, December 9, 2008

By	Dadofsix (Colorado Springs, CO USA) - See all my reviews

That's the question I kept asking myself as I re-read Simple Architectures for Complex Enterprises. Let me say at the outset that I'm totally open to the possibility that I missed the point--again!

The book starts off with an interesting discussion of complexity. Ok, not bad. Then, Sessions introduces the set-theoretic concepts of equivalence classes and partitions as means to reduce complexity. At this point, being a math enthusiast, I was well baited. By Chapter 5, where he first begins to discuss the SIP process, I had high expectations. By the time I completed Chapter 6, I was completely disappointed. His fundamental equivalence relations--synergistic and autonomous--are intriguing in their definition, but amount to being completely arbitrary and subjective. I found no real mathematical grounding at all, which is a major premise and selling point of his approach.

After reading about his type system, with its implementations and deployments, I came away feeling that I had read yet another description of how to do a functional decomposition (FD). This time, though, it comes wrapped in terminology that is pedantic. His "laws of partitions" are nothing more than heuristics for checking a FD:

- The First Law basically says that the FD is hierarchical. That is, a node can have only one parent.
- The Second Law states that the FD must make sense.
- The Third Law states that each level of the FD should contain 3-8 child nodes.
- The Fourth Law says that each child node in the FD should be about the same in scope, complexity, and importance as the other child nodes at the same level.
- The Fifth Law is not so much a FD rule so much as it is a statement about low coupling and high cohesion.

I think Roger Sessions is very smart and innovative (e.g., his metaphor of Software Fortresses is very well done). So, I want to give him the benefit of the doubt. But I don't think there's anything new here, folks. It seems to be a rehash of some Structured Analysis and Design concepts and other concepts from the past.

Someone please show me where I missed the boat!