“I have known Leon for many years now. He is one of the pioneers of precise UML modelling, and a highly effective trainer and consultant. His books contain both humour and insight.” October 20, 2009

Chris Raistrick, Director, Kennedy Carter
 

“Leon is, quite simply, one of the best modelers I have ever worked with. Having consulted on a broad spectrum of applications, he is especially adept at uncovering and understanding the underlying requirements for a system, even when he has not yet worked in the subject matter at hand. Leon then puts that understanding, along with his experience in embedded and scientific applications, to work as he determines which abstractions will lead to the most efficient model-based solution to the problem. With a great sense of humor and a love for teaching and consulting Leon is one of the most entertaining and engaging people you will ever meet.” October 30, 2007.

John Wolfe, President and CEO, Project Technology
 

“Leon was hired to provide training on Executable UML modeling. As a trainer, he was engaging and demonstrated knowledge in both previous application of the subject matter and approaches to applying it with respect to our product lines. I have also read Leon's books and interacted with him at various times since the training. I consider him to be an expert in his field.” September 14, 2007.

Top qualities: Great Results, Personable, Expert

Lee Riemenschneider
 

“Leon (along with other luminaries like Stephen Mellor) literally wrote the book on Executable UML, which is changing the way that software development is done, especially in the realtime, embedded & safety-critical world. Why shouldn't your documentation be the same as your code be the same as your high-level model? Leon explains how to do that, cleanly, crisply and clearly. A smart guy, a great speaker and a pleasure to work with.” September 13, 2007.

Richard Soley, Chairman and CEO, Object Management Group, Inc.

“I worked with Leon many times over the duration of his contract at St Jude Medical. I also attended a 4-day UML class he taught in-house. Leon is a great instructor. His course material is complete and his classes are well-prepared and interesting.
He enjoys his work and shows a lot of passion for good design and interesting technical challenges. Leon is a true expert and on the leading edge of object oriented design (and UML/xUML) concepts. He is a great resource when starting a new project or expanding an existing design. Leon is able to provide both theoretical and hands-on experience.” December 16, 2008

Melanie Gurunathan, Sr Software Engineer, St Jude Medical
 

“Leon lead the requirements analysis of the embedded software for a complex video production system. Leon brought to the project an infectious enthusiasm, good engineering judgment, and an inquisitive mind good at separating the wheat from the chaff. I would jump at an opportunity to work with Leon again.” August 25, 2008

Jonathan Sandoe, Sr Software Engineer, Ampex

Planning to actually use UML? Must read this book!

By Gary Marcoson February 3, 2002

Any developer who is currently using or is planning to use UML on a real project should read this book. Successful completion of one or more Class Diagrams is an essential step for every UML project. This book provides the developer with the information needed to create rock solid Class Models (Class Diagrams augmented with supporting documentation to enable review by other developers). The book is very detailed and yet is written in an easy-to-read and entertaining style. Numerous informative examples are included to reinforce comprehension of the essential topics.

For the beginning UML developer:
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The basic elements of the Class Diagram (Classes, Attributes, and Relationships) are defined simply and clearly. Categories of each of these elements are then enumerated. Each category is then supported by at least one easily understood example.
An especially useful spectrum of Class categories spanning from the concrete to the abstract is presented. The class categories of hard/physical, discovered, invented, simulated, specification, incident, interaction, and role are covered in detail.

For the intermediate UML developer:
--------------------------------------
Even if you have been building class diagrams for some time, you will likely benefit from several chapters on advanced relationship topics. These topics include Loops and Constraints, Advanced Generalization Relationships, Reflexive Patterns, Network Patterns, Linear Patterns, and Tree Patterns.

For the advanced process-aware developer:
--------------------------------------------
You will be intrigued by the introductory section "What is Executable UML?". This section contains a concise yet exciting description of where the UML is currently headed. For more details on this evolving aspect, you can read about the Action Semantics extension to the UML and the Model Driven Architecture initiative (MDA) of the Object Management Group.

More technical works should be written like this!!!!

By Lourdes C. Martinezon January 6, 2003

I've read more than my share of technical texts over the years. With a few exceptions, most are dry, difficult to understand and cover too much material without developing any topic particularly well.

Leon Starr's book "Executable UML: How to Build Class Models" is refreshingly different. Not only is it written in a uniquely engaging style, but it does a fantastic job of developing the concepts that go into Executable UML class modeling.

Furthermore, his introduction "What is Executable UML?" is the best concise overview of the topic I have *ever* read. In under 25 pages, Leon hits every major point of discussion in Executable UML in enough detail to provide real value for the reader. Although it's well worth reading for anyone who's interested in Executable UML modeling, I would especially recommend this chapter to anyone who is *new* to Executable UML, and wants to understand what all the fuss is about.

Leon's approach to the subsequent chapters on class modeling doesn't bog down the book with a complicated discussion of an abstract (and potentially complicated) topic. His discussion is clear, concise, with frequent use of examples to hammer home his points.

He always provides a brief scenario before he launches into a modeling example, giving a excellent context for why he used certain modeling techniques. For beginners in Executable UML, this is an excellent way to get into the mindset of modeling. More experienced readers can also benefit a great deal from the best practices discussed.

Another myth about technical texts is that good content = dry read. Not so! Leon's book is *very* entertaining. This has got to be one of the most pleasant technical reads out there. Interestingly enough, when I turned the final page, not only had I enjoyed the journey, but I found that I *really* understood the topic.

More books should be written like this! "Executable UML: How to Build Class Models" is the exception that *should* become the rule.

Excellent book

By Paul Clothieron August 20, 2003

I've had one of Leon Starr's other books, "How to Build Shlaer-Mellor Object Models" on my bookshelf for many years and used it as a constant reference for my OO training and documentation work. I have always liked the way Starr manages to simplify conceptual information in an engaging and down-to-earth manner - something that is close to my heart as a veteran educator.

"Executable UML" builds on the models he introduced in his previous book and moves from the S-M world to the executable UML world. I thought the book was very well written and gave a good, clear explanation of what Executable UML actually is and how it extends the UML. The examples Starr uses to explain some of the more abstract ideas and concepts were great and his treatment of relationships and associations was excellent I thought. As well as the clarity of the writing I particularly appreciated the sense of humor in this book - something sadly lacking in many methodology texts.

I've been using this book as well as Mellor and Balcer's book "Executable UML - A Foundation for Model-Driven Architecture" as references in developing xtUML online-learning courses and found them both invaluable.
Great book - highly recommend it.

Excellent about UML, not much about "executable"

By Lars Høidahlon March 4, 2003

I was disappointed with this book because there is nothing here about UML action language or constraints. That's what I thought "executable" meant, but I obviously got something wrong. The book is the best I have read class modeling, though. If you want to learn practical UML modeling, I strongly recommend this book.

In Alphabetical Order

Ampex

Led a team of software developers in modeling and writing code in C/C++ for a professional video special effects device. Models were entered and maintained in AutoCAD. We delivered working software before the hardware was complete. (2 years)

British Petroleum

Developed an extensive and detailed set of Shlaer-Mellor (class/state/action) models for a fully automated factory transport system for client AT&T. This is one of the first object model to C code generators ever built. (1 year)

Caterpillar

Developed executable UML models for equipment control and a Caterpillar systems engineering tool. (5 years 8 months)

Ericsson

Reviewed and refactored C++ / UML models for a cell network radio base station control subsystem. Normalized the underlying data and helped simplify the control scheme. (2 years)

KLA-Tencor

Developed executable Shlaer-Mellor (object/state/action) models for several of semiconductor measurement and test equipment projects. These models controlled robotic equipment, measurement and imaging hardware and tracked fab materials. (3 years 5 months)

Lockheed Martin

Helped develop executable UML models for an avionics network protocol, pilot interface and other avionics applications. (2 years 6 months)

Pacific Gas & Electric Company

I developed a contract management system with lifecycle automation entirely with 40k lines of database stored procedures using plpsql on PostgreSQL. This system interfaced with two separate GUI's Jquery web and an Eclipse rich client. (1 year)

Philips Medical Systems

This was actually ATL prior to purchase by Philips. Provided extensive training and helped requirements analysis and development of executable UML models for a new generation of ultrasound imaging systems. (2 years 5 months)

Project Technology, Inc.

Worked closely with Sally Shlaer and Steve Mellor to develop training materials for their software development method. Assisted on consulting assignments helping develop client models. I invented the use of post-its as classes in the early days of case tools. (1 year 2 months)

Saab AB

I am the primary MBSE consultant for both embedded and external combat fighter software. I provide training, mentoring and model development to a large body of engineers who are developing executable UML models. This is an ongoing project. In the past I have provide training and consulting to assist with the development of models for a military battle simulator and battlefield network architectures. (3 years 6 months)

Siemens Medical Solutions

Formerly Acuson Ultrasound before purchase by Siemens. I worked extensively with a team to build Shlaer-Mellor models (class/state/actions) to model the control software for the Sequoia ultrasound diagnostics station. (2 years 9 months)

St. Jude Medical

Developed executable UML models to manage interrupt based cyclical timing for embedded pacing devices. Helped develop models for managing a variety of pacing algorithms. Providing extensive training and assistance with client developer's models. (4 years 4 months)

US Navy

Under contract to CSC, I played an instrumental role in reorganizing the model development process for a large, complex joint services battle simulator (JSIMS) for SPAWAR. Assisted model developers building executable uml models simulating radar tracking, battle damage, amphibious transport, defensive weapons systems and ship navigation and communication. (2 years 3 months)

Varian, Inc

Unraveled an ugly modeling mess, reogranized the development process and helped build executable Shlaer-Mellor models for a gas chromatograph station. We successfully delivered a product with 95% model generated C/C++ code. (2 years)

Yourdon, Inc.

Worked closely with Steve Mellor and Paul Ward to learn and then teach their newly developed Ward-Mellor Structured Analysis and Design for Real-Time Systems course. I racked up a lot of frequent flyer miles teaching about forty 5 day training sessions for real-time/embedded systems students at Fortune 500 companies across the US. (1 year 1 month)