Using Pull Planning to Shrink Timetables
If you ask Felipe Engineer-Manriquez with McCarthy Building Companies, Lean construction principles can make a good project even better, shaving time off the schedule and thereby improving profitability.
One of the lynchpins of Lean is pull planning, a surprisingly low-tech method of whittling away fat from a project timetable based on working backward from the request (“pull”) of downstream customers. According to leanconstruction.org, pull planning “will often expose the need for smaller batches, just in time delivery, improved leveling of resources, and reduced lead times.”
Here’s how it works: All of the project players who supervise work — known as the “last planners” in Lean speak — gather in one room and “reverse engineer” the schedule using sticky notes placed on a giant board. Each person has his or her own color. Each note indicates what the person has committed to deliver on what date and what he or she needs from others in order to accomplish that goal. Starting with the desired completion dates, the team works backward to determine overlaps between tasks, tightening up time allowances along the way.
Engineer-Manriquez said the method is particularly helpful with complex projects and sections of the schedule where trades are highly dependent on each other.
The pull planning concept can be a big adjustment at first for some project participants, such as subcontractors who’ve never done it before, but Engineer-Manriquez said once they see success by completing tasks faster than usual, they quickly become devotees.
To get the most out of a pull planning session, Engineer-Manriquez said there are four words to keep in mind: can, will, did and learn.
Can: “‘Can’ is what’s possible,” he said. This is the work that can be accomplished within the pull planning period.
“You want to pull the phase of work that’s happening or just about to happen.” Focus on tasks that are no farther out than eight weeks, primarily because of the people and time it takes to conduct a pull planning session. Pull planning for an eight-week phase of work, Engineer-Manriquez said, takes a three-hour commitment from the entire team.
Will: These are the tasks to which people commit during a pull planning session. Each commitment is memorialized on a sticky note.
Did: The next phase is “did.” This is where the team evaluates whether or not they achieved their goals. “If we did it, great,” he said. “If not, then we go onto the next conversation and ‘learn.’ We need to figure out why we didn’t get there or why someone didn’t make a commitment.”
Learn: As part of the learning process, the team determines the PPC, or the “percent plan complete,” for the work specified in the pull planning period. The PPC analysis looks at tasks completed versus not completed. If everyone hit their goals, the PPC would be 100 percent. For a first effort, Engineer-Manriquez said it’s not unusual for a project to achieve a PPC of only 30. After a root cause analysis and a re-commitment from the participants, however, he said a PPC of 75 or higher is not unheard-of.
At its best, Engineer-Manriquez said, pull planning makes everyone feel like an equal team member and requires them to think about their own processes like never before.
"The real value," he said, "is in the conversations. That’s where people speed up plans and solidify commitments. That’s where the magic happens.”
Kim Slowey is a writer who has been active in the construction industry for 25 years and is licensed as a certified general contractor in Florida. She received her BA in Mass Communications/Journalism from the University of South Florida and has experience in both commercial and residential construction.