Rick Steiner (July 2009) Co-Chair, SysML 1.2 Revision Task Force Co-Author, "A Practical Guide to SysML" (ISBN 978-0-12-374379-4)
"I'm extremely grateful to Dr. Darren Kelly for providing such an invaluable contribution to the development and robustness of SysML! He is by nature a man of practical vision, and immediately saw the value of SysML in solving real problems. He took the initiative to seriously test the language, and was the first person to completely capture a non-trivial example problem (Annex A of the SysML spec) in a real modeling tool. In the process he revealed many subtle shortcomings of the language, as well as the tool's implementation of it.
Dr. Kelly has also been very generous in sharing extensive system modeling and analysis experience, including many subtle and elegant solutions to difficult modeling problems. He has a remarkably deep understanding not only of UML and SysML arcana, but also of the practical implications of applying them to solve real-world systems engineering problems.
Dr. Kelly is the kind of innovative, energetic, tenacious person you need when you face an extremely difficult, complex systems engineering problem, but have no idea how to solve it!"