Jonathan D. Addelston has been active in the Software Engineering Institute (SEI) process improvement community since January 1989, prior to the creation of the first Process Maturity Questionnaire. He was a cofounder of the first Software Process Improvement Network (SPIN) in Washington, DC, and is currently its leader, as a program chair. Mr. Addelston cochaired the first CMM^® and Software Engineering Process Group Workshop with the SEI. He was the founding VP for Software Product Development at the Software Productivity Consortium; the VP for Software Engineering at PRC, Inc; and the CTO at BDM International. In 1996, he founded his current systems and software engineering consulting practice focusing on enterprise architecture, process improvement, business process reengineering, and independent verification and validation. One of his first software projects was the jet select logic for the NASA Apollo Lunar Excursion Module, just after Mr. Addelston graduated from MIT with a degree in mathematics in 1965 (before the school had an undergraduate computer science major). He has collaborated with his coauthor, Theresa A. O'Connell, since 1991. He can be reached at jdaddelston at alum.mit.edu.