Research and Publications
Our industry is in need of better methodologies for production management and control and while the Last Planner System® has been around for a long time, most implementations in the industry remain limited in scope and near-term focused. The materials presented here represent state-of-the-art research in production planning and control including work we had done on improving the Last Planner System® metrics to better integrate near-term and long-term goals when planning production.
The Workplan
When LPS® was first introduced, it focused on improving the chances that when something is scheduled to start, it starts and finishes as planned. It shifted the focus from simply starting things to "actually" finishing them, a subtle yet significant distinction. Reliability was measured based on the percentage of promises completed, Percent Plan Complete or PPC (often referred to as the DID part) at the end of a workplan compared to the promises made at the start of the work plan (i.e., the WILL part). When tasks did not happen as planned, they were analyzed to identify the root causes and implement countermeasures to improve the planning system.
The Lookahead
Initially, LPS® focused on the near-term work represented by weekly work planning and lookahead (or make-ready) management. The premise was that through better constraint identification and management, teams could improve the chances of having properly sequenced work to do and finishing work when planned. In other words, with enhanced constraint management, teams will have a better opportunity to align what they WILL be doing with what they CAN be doing and what they SHOULD be doing.
The earliest versions of LPS emphasized improving the near-term plans based on pre-existing project schedules developed using the Critical Path Method (CPM). Later, additional metrics were introduced, such as Task Anticipated and Tasks Made Ready to measure the reliability of the lookahead planning process, but those metrics were rarely used in practice. While the evidence shows that reliability improved as measured by PPC, teams found that they could achieve high reliability in the near term yet still missed their targets.
The Pull Plan
“Pull Planning,” or reverse-phase scheduling, was added later to improve how scheduling and work sequencing are done in the first place (see 2016 Current Process Benchmark for more detail). “Pull” was interpreted literally, and “pull planning” was done by working backward from target milestones to uncover handoffs and the relevant work contributing to achieving the target. The initial intent was to detail the milestone-level schedule, identify work phases and phase handoffs, and then focus on breaking down the tasks and sequencing the work to reveal the handoffs. While this has helped improve work sequencing, simply working backward from targets will not produce a well-balanced process flow or crew flow.
The Takt Plan
When the 2016 Process Benchmark was released, there was some awareness that takt planning helped improve LPS® implementations.
LPS® as a production planning and control system has continued to improve in practice. Takt was recognized as an LPS® work structuring method in the 2020 Benchmark Additional enhanced metrics (initially introduced by vPlanner) were added to measure the alignment between what a team SHOULD do, CAN do, WILL do, and DID. Clear definitions were added to distinguish what SHOULD be done (or required, or essential work) from backlog work (or work that can wait until it becomes required). New advanced metrics were added to measure performance, such as Commitment Level (CL), Percent Required Complete (PRC), and Milestone Variance (MV).
Enhanced LPS® Metrics Primary Sources
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IGLC 2016 - Aligning Near-Term and Long-Term Planning for LPS® Implementations
S. Emdanat and M. Azambuja
This paper, co-authored by Samir Emdanat, President of vPlanner, is a must-read for anyone interested in advanced LPS® metrics. It was presented in 2016 as a keynote at the IGLC conference in Boston. The paper introduced the vPlanner long-standing metrics of Commitment Level (CL), Percent Required Complete (PRC), and Milestone Variance Metrics (MV) and their effect on team performance. Years later, those metrics became the basis for expanding the LPS® framework as presented in the 2020 Benchmark by P2SL. To our knowledge, vPlanner is the only commercial software that supports those metrics.
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LCI Journal 2020 - The New LPS® Metrics: What They Are, Why They are Needed and Where They are Used
D. Christian and M. Pereira
This paper picks up where the IGLC 2016 paper left off and discusses the impact of the new LPS® metrics of Commitment Level (CL), Percent Required Completed (PRC) and Milestone Variance (MV) had on projects. The paper provides guidance on how to apply and interpret the metrics during the various stages of a project from validation, through design, and during construction. Further, it emphasizes the importance of distinguishing Required Tasks (RT) from Non-Required Tasks (NRT) or Backlog.
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LCI Journal 2021 - 2020 Current Process Benchmark for the Last Planner® System of Project Planning and Control
G. Ballard and I. Tommelein
Created by P2SL at UC Berkeley, the 2020 LPS® Benchmark embodies the most recent advancements of the Last Planner System®. Key among them is the expansion of the system to cover both near-term and long-term planning horizons and the introduction of advanced new metrics that the vPlanner team had designed to align the near-term priorities with the long-term project milestones.
Commitment Level (CL): CL measures if the team commits to the right amount of work on the work plan to keep all downstream targets on track. When CL is less than 100%, the team is under committing and will be late at the end of the work plan cycle unless they replan or accelerate the work. CL is measured at the start of a work plan cycle.
CL = Required WILL / SHOULD
Percent Required Complete (PRC): PRC measures if the team completes enough required tasks at the end of the work plan cycle, regardless of whether they had promised to do them or not. This is important to incentivize the team to get more done when CL is low at the start of the work plan cycle. The PRC goal is 100%. PRC is measured at the end of the cycle to capture any replanning or acceleration effects the team may have done between starting a work plan and completing it.
PRC = Required DID / SHOULD
Milestone Variance (MV): MV measures the difference between the remaining work when pulled from a milestone forecast against the milestone target date. It is important to measure MV as the prioritization of required tasks will change based on the milestone date. Milestone variance is measured at the start of a work plan cycle.
Takt Planning and Production System Design
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IGLC 2016 - A Framework for Production Tracking when using Takt and LPS®
S. Emdanat, M. Linnik, and D. Christian
This paper proposes a framework for incorporating direct field labor hours and costs into an overall production strategy centered on Takt Time Planning (TTP) and the Last Planner System®. It discusses the basis for the vPlanner Production Tracker tool which tracks labor hours including budgeted, estimated, and actual as an early indicator of risk on projects. The paper outlines the improved workflow processes and presents an analysis of the data collected over several months from a pilot project.
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IGLC 2022: Takt Planning: An Enabler for Lean Construction
I. Tommelein and S. Emdanat
Some view Takt as a tool for construction planning, but is it just a tool? This paper shows that takt planning can serve as the basis for designing the production system as a pull system. It leads to improved reliability during execution through improved process stability. It provides focus to continuous improvement efforts to identify and remove bottlenecks and improve flow. The contribution of this paper is to highlight that a lean journey that starts with takt may proceed with implementing numerous lean tools and methods other than those directly pertaining to takt itself.
Integrated Project Delivery (IPD)
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IGLC 2015 - Introducing Four-Phase Project Delivery
D. Christian, J. Bredbury, S. Emdanat, F. Haase, and Z. Rubel
This paper is the result of the collaboration among several IPD pioneers. It proposes a framework for improving project performance. It presented the concept of Four-Phase Project delivery as a practical framework for analysis of a project’s current state against an ideal state. The analysis can then be used to produce focused improvement strategies to reduce the variance from the ideal state. The paper was cited in several publications including the recently published book “Integrating Project Delivery”.
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Book Chapter - The Integrated Project Delivery (IPD) Method
S. Emdanat and D. Christian
Chapter 9 of the “Modern Construction: Lean Project Delivery and Integrated Practices” book was co-authored by Samir Emdanat (vPlanner), Digby Christian (Sutter Health). In it, they discuss the origins of IPD and its successful implementation on dozens of Sutter Health projects. The chapter provides an in-depth look at their hands-on experience as they implemented IPD on several large-scale projects and the lessons learned and the best practices they have compiled over the years. The book provides a unique look at how breakthrough change was implemented through the detailed study of information flow and value stream mapping.
Enhanced LPS® Metrics: Additional Readings
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IGLC 2016 - A Framework for Production Tracking when using Takt and LPS®
S. Emdanat, M. Linnik, and D. Christian
This paper proposes a framework for incorporating direct field labor hours and costs into an overall production strategy centered on Takt Time Planning (TTP) and the Last Planner System®. It discusses the basis for the vPlanner Production Tracker tool which tracks labor hours including budgeted, estimated, and actual as an early indicator of risk on projects. The paper outlines the improved workflow processes and presents an analysis of the data collected over several months from a pilot project.
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IGLC 2017 - The Last Planner System® - The Need for New Metrics
G. Samad, F. Hamzeh, S. Emdanat
Over the years dozens of metrics have been proposed to track production when using the Last Planner System®. This paper offers an overview of the various metrics proposed in the literature. It also proposes new metrics and details their calculation method to measure aspects not yet supported by a measurement metric. The paper provides a great reference point for anyone interested in the evolution of production tracking metrics and their definition.
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IGLC 2017 - Introducing New Capacity Planning Metrics in Production Planning
L. Rizk, F. Hamzeh, and S. Emdanat
This paper introduces new capacity planning metrics to measure and understand the current state of capacity planning on construction projects. The goal is to inform planners about the status of load vs. capacity when they make choices regarding commitments.
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ASCE 2019 - Advanced Metrics for Construction Planning
F. Hamzeh , G. Samad, and S. Emdanat
This paper expands on the research in the IGLC 2016 and 2017 papers and presents a detailed analysis of the LPS metrics proposed in the previous research. The analysis is based on several highly successful projects that implemented the enhanced Last Planner System® as presented in the 2020 Benchmark.
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Book Chapter - Advanced Last Planner System Metrics for Construction Planning and Control
F. Hamzeh, S. Khalife, G. Samad, L. Rizk, H. Abou-Ibrahim, M. Al Hattab, and S. Emdanat
Chapter 16 of the “Modern Construction: Lean Project Delivery and Integrated Practices” book is dedicated to discussing the various approaches to measuring reliability and performance in production systems. Key among them are the new LPS® metrics of Commitment Level (CL), Percent Required Complete (PRC), and Milestone Variance (MV).