Its full name is the Last Planner System® of Production Control. Production control is necessary on projects to support working toward planned accomplishments, doing what can be done to move along a planned path, and when that becomes impossible, determine alternative paths that accomplish desired goals. The term Last Planner System® is a registered trademark of the Lean Construction Institute, which is why the “®” symbol should appear when first used in a document.

The Last Planner System is a holistic system, meaning that each of its parts is necessary to support lean project planning and execution. Resist the temptation to treat the system as a menu from which you select only the parts you want to use. The system is organized into six major parts.

Figure 1: Last Planner System (Courtesy Project Production Systems Laboratory)

The first part, Project Execution Planning, is a recent addition. It recognizes that before a project is planned there needs to be an assessment as to the project’s feasibility. Project objectives must be clarified, with an acceptable understanding of achievable goals, opportunities, risks, and constraints. On projects using an integrated form of agreement contract method this assessment is made by all parties part of that agreement. On other projects parties responsible for funding the project will make this assessment. In those cases, sharing the assessment with the project team aids their ability to deliver the project successfully.

The next two parts focus on identifying the work that should be done to complete a successful lean project. Master Scheduling follows Project Execution Planning. The master scheduling work is focused on identifying major milestones that help gauge the pace at which the project will progress if it is to be successful. Normally milestones are completion dates for each of the major project phases and dates for releasing the purchase of major long lead building items.

Ideally both design phase and construction phase last planners participate in developing the master schedule. The term “Last Planner®” (also a registered trademark of the Lean Construction Institute) refers to the people on the team responsible for making the final assignment of work to specific performers and ensuring they have the materials, equipment and information available to complete their assignments. During the design phase, last planners are typically architectural and engineering project managers. During the construction phase, last planners are typically foremen and superintendents for the trade contractor crews.

Phase Scheduling is done ideally two to three months before the beginning of each phase. Phase in this context refers to a portion of the project that makes sense to consider as a complete unit. The phase breakdown for a project will depend upon the size and complexity of the work, with beginning and completion milestones for phases identified during the master planning. Phase scheduling develops an agreement between last planners on how all the work between those two milestones will be completed.

Phase scheduling utilizes a pull planning approach, wherein last planners are very clear about the sequence of requests and commitments they are making with each other. The approach follows a central lean practice of developing flow by starting with the final condition required to complete a phase, and building the sequence of work through a series of customer requests and performer promises to define clearly how work will be released from one operation to another. These phase scheduling sessions are important opportunities for the team to determine how to pace the work so that it progresses at a steady rate with limited variation to workflow and crew sizes.

The fourth part of the Last Planner System focuses on ensuring that work can be done. It is through Lookahead Planning that last planners evaluate whether there are constraints to upcoming tasks identified during phase scheduling. Most teams look ahead six weeks when, though on complex projects a longer time horizon may be warranted.

Constraints are conditions that prevent a planned task from being completed, and include concerns such as labor and material availability, equipment access, construction document conflicts, and required permits.

Constraints are identified on a log, with responsibility for removing a constraint identified along with a promise from a specific person for removing each constraint by a certain date. Insufficient lookahead planning is often the single most factor in project workflow breakdowns, so it is vital that the team attend to lookahead planning in a diligent manner. The lookahead planning also includes the refinement of tasks identified during phase scheduling into more detail, as required by a better understanding of the work.

There are two additional aspects of lookahead planning that need consideration. First, those tasks in the phase scheduling that were not broken down to the level of operations sufficient for daily and weekly execution planning need to be developed into further detailed tasks. Second, tasks should be designated as ‘critical,’ meaning they are essential to maintaining workflow, and ‘non-critical,’ meaning that their start can be deferred without impacting workflow. This second aspect is relatively new and not yet widely practiced.

The fifth part of the Last Planner System focuses on what each last planner will do to fulfill the promises made during the phase planning. This is accomplished through project Weekly Work Planning, wherein each last planner identifies the tasks their team will complete each day of the following week. Reliability is extremely important in developing these shared plans.

The sixth part of the Last Planner System focuses on learning from what the team did. Learning is a daily action for lean project teams. The Last Planner System provides two specific opportunities for learning. One is through the daily coordination meeting, often called the daily huddle. In this brief stand-up meeting, last planners confirm whether their teams accomplished the planned work that day, and if not agreed upon adjustments required to stay on plan for the week. These daily adjustments are vital, as daily adjustments are easier than weekly adjustments, which are much easier than monthly adjustments.

The other learning opportunity provided by the Last Planner System is through the analysis of a few key metrics.

• Percent Plan Complete, a measurement of the percentage of weekly planned tasks that were completed as planned.
• Tasks Made Ready, a measurement of the percent of tasks identified during phase planning that were ready to begin as planned.
• Tasks Anticipated, a measurement of the number of tasks in a weekly plan that were identified in the look ahead plan.
• Commitment Level, a measurement as to how effectively last planners are assigning tasks designated as ‘critical’ versus tasks designated as ‘non-critical’ during Lookahead Planning.
• Frequency of Plan Failures, a measurement of the number of planning failures in a defined range of categories, Reasons for Variance, over time. This helps the project team assess root causes responsible for work not being completed as planned.

There are two important considerations in making your implementation of the Last Planner System successful. First, you won’t leverage its full potential in a command and control environment. Management practices need to be aligned with the lean Respect for People principle and project leaders need to see themselves as coaches and facilitators of the planning and learning by last planners on the project.

Second, the use of the Last Planner System is a discipline, and like any other discipline such as an athletic activity or playing a musical instrument requires continued daily practice to first become proficient and then ultimately master. Make it the cornerstone of project team collaboration and you have taken a large step toward implementing a lean project.