Greg and Glenn Ballard first met on a project in Texas in 1979 and began a lifelong relationship of friendship and collaboration.

Greg and Glenn had a long history of working together in research, consulting, and promoting lean construction to the industry.  With a focus on developing new theories and their practical application, Greg and Glenn went on to invent the Last Planner System.  In addition to founding the Lean Construction Institute, Greg and Glenn were also among the founding members of the International Group for Lean Construction and Lean Project Consulting.