An Abridged History of the Last Planner System

How the First Planner System Supports the Last Planner System

Before there was a Last Planner System, there was a struggling oil and gas project near Houston, in a place called Chocolate Bayou. It was 1979. The oil industry was in crisis. The project was so far behind schedule and so far over budget that a new project manager, Howard Peek, concluded he had nothing to lose and brought in people willing to try radical strategies. On that team was Greg Howell. The Brown and Root manager assigned to work alongside them was Glenn Ballard. What happened at Chocolate Bayou did not just turn a project around. It planted the seed of a production planning system that would eventually be used on construction projects around the world.

The Last Planner System was not born in a university seminar room or a consulting firm. It was born in the field, by people who were deeply embedded in the real conditions of construction work and who refused to accept that the dysfunction they observed was inherent to the industry.

The Origins of the People Behind the System

Greg Howell learned the value of collaborative work from the commanding officer of a construction battalion on which he served. He earned civil engineering degrees from Stanford and developed a specialty in using time-lapse photography to analyze construction activities the discipline of observation, of watching what was actually happening on a site in order to generate ideas about improving productivity. His conviction was simple: the more clearly you could see what was happening, the more clearly you could see how to improve it.

Glenn Ballard came from a different background. He had been a pipefitter’s apprentice before becoming an area construction engineer for Brown and Root, working mostly on oil and gas projects. He brought a direct understanding of construction from the inside what it felt like to be the person doing the work, and what made that work harder or easier than it needed to be.

At Chocolate Bayou, working together for the first time with a team that included Professor John Borcherding and Professor Richard Tucker from the University of Texas, Greg and Glenn helped turn the project around and increase productivity by ten percent. But Glenn was not satisfied with ten percent. The experience led him to develop the concept of Crew Level Planning the foundational idea that the people in the field who are actually doing the work should be involved in planning it. He presented this concept in a paper called Crew Level Planning at a conference at the University of Texas in 1981. That paper is, in retrospect, the first expression of what would eventually become the Last Planner System.

The Academic Phase and the Lean Discovery

Greg and Glenn’s work caught the attention of universities. Greg joined the faculty at the University of New Mexico in 1987. Glenn joined the University of California, Berkeley in 1989. Academic positions gave them both a new avenue for exploring construction productivity and brought them into contact with other researchers doing parallel work. The most significant of those connections was with Lauri Koskela, whose 1992 paper on applying production philosophy to construction drew on research extending from Japan in the early 1950s through the early 1990s the body of work that many people recognize as lean production.

Shortly after, the three discovered The Machine That Changed the World the book that documented how Toyota’s production methods enabled it to supplant General Motors as the world’s largest automaker. Reading it, Greg, Glenn, and Lauri realized that what they had been developing and implementing in construction was fundamentally similar to what the book described happening at Toyota. The connection was not just philosophical the practices they had been developing from field experience aligned with the production system principles that Toyota had been refining for decades. It was at this point that they adapted the term Lean for their work in construction productivity, even though the underlying work had been underway for more than a decade before the term Lean construction existed.

In 1993, Glenn, Lauri, and Luis Alarcon founded the International Group for Lean Construction named at the group’s first conference that year. IGLC was primarily a community of academic researchers sharing field-based research and seeking to understand how Lean Construction ideas could be applied more broadly. At that first conference, Glenn introduced the term “last planner” naming for the first time the concept at the center of the system he had been developing.

How the System Evolved

The Last Planner System developed through exactly the iterative improvement process it teaches. Each component was added when field experience revealed a gap that the existing practices could not close.

The initial requirement was straightforward: front-line supervisors the last planners should plan their work week based on what they actually knew could be accomplished, not based on what a master schedule dictated. This produced the Weekly Work Planning practice. When crews planned only the work they could complete, and committed to completing it, the reliability of the weekly production plan improved significantly.

With weekly work planning came a way to measure that reliability. Percent plan complete the number of assignments finished in a week divided by the total assignments made for the week was introduced by Glenn in a 1994 paper presented to the Northern California Construction Institute. PPC gave teams an honest metric for how reliable their planning was. When complemented by variance analysis to understand why misses occurred, PPC became the feedback mechanism that allowed teams to learn from their performance and improve their planning reliability over time.

Make-ready planning was the next addition. Glenn and Greg first described it in print in a 1994 IGLC paper called Stabilizing Work Flow. The need for it emerged from a specific field observation: a project could achieve high PPC crews completing what they committed to and still fall behind schedule, because higher productivity outpaced having the materials and conditions ready for the next phase of work. Make-ready planning addressed this gap by systematically looking ahead to identify and remove the constraints that would prevent planned work from being executable.

Phase planning came later in the 1990s. The first pull planning session Glenn remembers was from a project team workshop for a Linbeck Group project in 1998 or early 1999, where a suggestion was made to schedule backward on the wall working from the required completion milestone backward through the sequence of work to identify what each trade needed to do, and when, to make that completion achievable. That approach captured the fundamental principle that the people responsible for the work must help develop the plan they will execute.

Each evolution was driven by the same process: observe what the current practice cannot do, develop a practice that addresses the gap, test it in the field, refine it, and add it to the system. The Last Planner System continues to evolve on exactly this basis, with contributions from many practitioners and researchers. It is likely, as Glenn has acknowledged, that it will never be fully complete it is, appropriately, subject to ongoing continuous improvement.

Here are the practices that emerged from specific field-observed gaps and the problems each was developed to solve:

• Weekly work planning solved the problem of crews being assigned tasks they could not complete, creating chronic task switching and reduced productivity
• Percent plan complete solved the problem of having no honest measure of planning reliability, making learning from misses impossible
• Make-ready planning solved the problem of high weekly reliability masking inadequate preparation for upcoming work
• Phase planning solved the problem of the people doing the work having no involvement in designing the sequence they would execute

What the System Is Actually About

The Last Planner System is based on a specific understanding of what makes construction production reliable: people need clear, productive conversations about their commitments to perform work, and their requests need to be heard and addressed so they can make those commitments honestly. The system is a framework for having those conversations for ensuring that requests are understood, that commitments are genuine rather than compliant, and that the feedback from actual performance informs the next planning cycle.

That understanding was present in Glenn’s Crew Level Planning paper in 1981. Every practice added since has been in service of making those conversations better more informed, more honest, more productive, and more connected to what is actually happening in the field. If your project needs superintendent coaching, project support, or leadership development, Elevate Construction can help your field teams stabilize, schedule, and flow.

The Last Planner System came from the field, was refined through the field, and continues to be developed through the field. That is why it works. And that is why the two superintendents at the beginning of this story and thousands like them have felt the weight lift from their shoulders when they finally learned to use it.

On we go.

Frequently Asked Questions

Where did the Last Planner System come from?

It originated from field work by Glenn Ballard and Greg Howell at a struggling oil and gas project in Chocolate Bayou, Texas in 1979. Glenn’s 1981 paper on Crew Level Planning was the first formal expression of the core idea that people doing the work should be involved in planning it.

When was the term “last planner” first introduced?

At the founding conference of the International Group for Lean Construction in 1993, where Glenn Ballard introduced the term to describe the front-line supervisors who are the last people in the planning cycle before work is actually executed.

What is percent plan complete and why was it developed?

PPC measures the number of weekly planned tasks actually completed as a percentage of those committed. It was developed because without an honest measure of planning reliability, teams had no mechanism for learning from misses and improving their planning over time.

Why was make-ready planning added to the system?

Because field observation revealed that high PPC scores did not prevent schedule slippage when teams outpaced the preparation of materials and conditions needed for the next phase. Make-ready planning addresses this by systematically identifying and removing constraints before crews arrive to execute.

How does the Last Planner System continue to evolve?

Through the same process that produced it field observation revealing gaps that current practices cannot close, development of practices to address those gaps, field testing and refinement, and integration into the system. Glenn Ballard and Iris Tommelein released an updated benchmark in 2020, and the system remains subject to ongoing improvement.