Understanding the Last Planner System in Construction

By

Josh Krissansen

Last Updated Jun 15, 2026

By

Josh Krissansen

On many commercial Australian projects, delays often begin when work is released before it is ready. Design information may still be unresolved, materials may not be confirmed, or access and preceding trades may not be in place. Programmes can still show credible dates, but reliability breaks down at trade handoffs where sequencing and readiness matter most.

Developed in the 1990s, the Last Planner System (LPS) is a collaborative planning system designed to directly target this failure point by empowering the people delivering the work to manage short-term scheduling.

It’s built around five planning conversations: Should, Can, Will, Did, and Learn, which run through the entire cycle. The Last Planner System (LPS) is a collaborative, commitment-based planning process designed to improve workflow reliability and predictability on construction projects. 

When applied with discipline, the result is measurable: less rework, reduced programme volatility, and plans that are executable rather than theoretical.

In this article, we explain how the LPS improves schedule reliability and how teams use trade-level commitments to reduce rework, false progress, and downstream claims.

5 planning conversations

The Last Planner System is built around a continuous cycle of five key planning conversations that drive the entire process:

1. Should

   “What should be done?” This initial stage involves defining the project's overall scope, milestones, and high-level sequence. It establishes what the project team should be doing to achieve the owner's objectives, typically resulting in a Master Schedule or "Pull Plan" for a major phase.

2. Can

   “What can be done?” This critical step focuses on ensuring the work is ready to start. The team looks ahead, usually 3–6 weeks, to identify and remove constraints that would prevent crews from completing their planned work. This includes verifying that necessary materials, information (drawings, specs), equipment, labour, and prior work are all available and ready. It determines what can actually be done, converting the "Should" into feasible tasks.

3. Will

   “What will be done?” This is where detailed, short-term commitments are made. The Last Planners (foremen, trade supervisors) collaboratively select tasks from the "Can" list that are fully prepared and commit to executing them in the coming week. This conversation results in the Weekly Work Plan (WWP), clearly stating what will be done by whom and when, ensuring reliable workflow.

4. Did

   “Did we do what we said we would do?” At the end of the week, the team reviews the performance against the commitments made in the "Will" conversation. The primary metric is Percent Plan Complete (PPC), which measures the ratio of tasks completed versus tasks planned. This conversation determines what did happen, establishing accountability and providing crucial data for the final step.

5. Learn

   “Why didn’t we do what we said we would do?” This is the improvement engine of the system. The team analyses the root causes for any tasks that were not completed (low PPC). By openly and non-punitively discussing why the plan failed, the team identifies systemic issues and develops action items to prevent recurrence.

Last Planner System process steps

The LPS follows a structured planning workflow that connects contractual milestones to daily site execution. Each step reduces uncertainty by removing assumptions and managing constraints before they disrupt work.

Step 1: Build the master schedule and milestones

The process starts by establishing the high-level programme and contractual milestones. This includes defining major phases such as structure complete, watertight, services rough in, and practical completion.

These milestones set clear boundaries for phase planning and pull planning workshops, and make key handoff points between major work packages visible early. At this stage, teams are defining what should happen to meet contractual obligations before testing feasibility or making delivery commitments.

That distinction is critical. It separates required outcomes from executable work and prevents assumed dates from being treated as promises. This keeps the conversation explicit, practical, and tied to contractual reality.

Step 2: Run phase scheduling and pull planning

Phase scheduling focuses on a specific milestone or phase. Teams work backward from the milestone to define task sequences and trade handoffs.

Task durations are confirmed by the crews who will perform the work, rather than relying on assumed productivity rates. Dependencies between trades and work areas are made explicit so teams can test whether the work can be done under real site conditions.

This makes the Can conversation practical. It exposes sequencing conflicts, access issues, and prerequisite risks early, before they turn into site delays or last-minute replanning.

Step 3: Do lookahead planning and make ready

Lookahead planning reviews upcoming work over a three to six-week window. The focus is on identifying anything that would prevent tasks from starting as planned.

Typical constraints include unresolved design, missing materials, access limitations, inspections, or approvals. Each constraint is assigned an owner and cleared before the task is released.

This step sharpens the Can conversation by ensuring tasks are executable before they enter the weekly plan.

Step 4: Set weekly work planning and reliable promises

Weekly work planning brings trade foremen and site leadership together to set commitments for the week ahead. Only constraint-free tasks from the lookahead plan are committed.

Promises are made by people who control labour and sequencing, and commitments are made visible to all affected trades, reducing clashes and misalignment. This confirms the Will conversation for what will actually be delivered during the week.

Step 5: Hold daily huddles and clear constraints

Daily huddles provide short, focused coordination on-site. Teams confirm progress against weekly commitments and surface new blockers as soon as they appear.

Work is resequenced immediately where needed to protect flow and avoid trade clashes. This keeps the Will conversation current as site conditions change.

Step 6: Measure percent plan complete and capture reasons for variance

Percent Plan Complete is calculated by dividing completed tasks by planned tasks for the week. Missed commitments are reviewed without blame.

Teams record reasons for variance such as design delays, material shortages, weather, access issues, or coordination failures. These learnings are fed back into lookahead and phase planning. This closes the Did and Learn conversations and drives continuous improvement across the construction planning system.

Last Planner System benefits for construction teams

LPS is based around five planning conversations that govern how work is prepared, committed, delivered, reviewed, and improved. Foremen and supervisors commit only to tasks they know can be completed, based on real constraints, labour availability, and trade sequencing.

These conversations create a disciplined way to manage readiness and commitments at the point where work actually happens, rather than relying on assumptions locked into a master programme.

At a practical level, the LPS improves programme reliability by replacing assumed dates with trade-level commitments. Work is only released when it is genuinely ready to start. That reduces construction programme volatility and creates predictability that supports cash flow, reporting, and client confidence.

Increased programme reliability and predictability

LPS shifts planning away from theoretical critical path logic and toward executable work plans. Commitments are set by foremen and supervisors who control labour, sequencing, and access on site.

Lookahead planning surfaces design gaps, material shortages, access issues, and approvals early, while there is still time to resolve them. Milestones are met more consistently because constraints are removed in advance, not managed after failure.

Infrastructure projects in Victoria using digital LPS have shown measurable improvements in programme performance, cost control, safety outcomes, and quality. The gains came from earlier constraint removal and more reliable weekly commitments, not heavier reporting.

Reduced waste and better use of labour

LPS helps prevent crews from starting work in areas that aren’t ready or are still constrained. Idle time caused by unfinished handoffs, missing materials, or unresolved RFIs is reduced because tasks are screened for readiness before release.

Task sequencing aligns with actual site conditions, limiting rework and avoiding stop-start productivity. For subcontractors, this protects margins by reducing remobilisation and lost time caused by broken handoffs.

Stronger collaboration across trades and site leadership

Pull planning makes trade handoffs explicit rather than assumed, with dependencies visible so downstream impacts are understood before work is committed.

Daily coordination replaces late escalation through emails and reports, keeping site teams aligned around a shared plan rather than separate trade schedules that only line up on paper.

Clear accountability without blame

Weekly commitments are made visible, owned, and reviewed as a group. Percent Plan Complete (PPC), which measures the percentage of weekly commitments completed on time, is used to measure planning reliability by tracking how many promised tasks are completed as planned.

When commitments are missed, teams record and analyse the reasons. Accountability lies with constraints and system issues, such as design, access, or supply, not with individual fault. This creates learning without blame.

Better executive visibility into delivery risk

PPC trends provide an early signal of planning quality, while variance reasons expose systemic risks such as documentation gaps, procurement delays, or access constraints.

This gives leaders the ability to intervene earlier, before issues surface in cost reports, extension of time claims, or recovery programmes, thereby improving predictability and governance without adding to the reporting burden on site teams.

Who participates in the Last Planner System?

The LPS only works when the planning authority sits with the people who control the work. Each participant plays a specific role in making, supporting, or protecting commitments. When ownership is unclear, planning becomes symbolic and reliability breaks down.

• Last planners

  Last Planners are typically trade foremen or crew leads for each subcontract package. They control labour allocation, sequencing, and short-term execution on-site.
  They make weekly commitments during planning sessions and are responsible for delivering the work promised or flagging constraints early. Their input is central to phase planning, lookahead planning, and weekly work planning because they understand what is executable under current site conditions.

• Superintendents and site managers

  Superintendents and site managers facilitate phase planning, lookahead planning, and daily huddles. Their role is to coordinate sequencing and handoffs across trades and maintain flow across work areas.
  Once constraints are raised, they take ownership of clearing them or escalating where required. They protect weekly commitments and ensure planning discipline is applied consistently, rather than allowing ad hoc resequencing to undermine the plan.

• Project managers and contract administrators

  Project managers and contract administrators set master programme milestones and contractual targets. They align short-term commitments with budget, programme, and client expectations.
  They resolve constraints outside site control, such as design decisions, approvals, or commercial issues. Their role is to support site teams and protect viability, not to override trade-level commitments once they are made.

• Project engineers

  Project engineers manage RFIs, shop drawings, and technical clarifications that affect readiness. During lookahead planning, they identify and close design-related constraints before tasks are released.
  By resolving information gaps early, they prevent unresolved documentation from flowing into weekly plans and disrupting delivery.

• Subcontractors 

  Subcontractors support their foremen by providing realistic input on durations, resources, and sequencing. They assign appropriately resourced crews to planned work and consistently participate in planning and coordination sessions.
  
  They also share accountability for handoffs and downstream impacts, rather than treating planning as an individual foreman's responsibility.

• Owners and client representatives

  Owners and client representatives participate selectively in master milestone and major phase planning. They provide clarity on priorities, access constraints, and sequencing sensitivities that affect delivery.
  
  They do not participate in weekly or daily planning. Instead, they use LPS outputs to gain confidence in delivery reliability, not to direct work or reset commitments at the site level.

Implementation best practices for the Last Planner System

Breakdowns usually stem from who participates, how commitments are handled, and whether planning discipline is protected as site pressure builds.

The practices below target the most common failure points seen on live Australian projects.

Practice 1: Start collaborative planning with the right last planners

Collaborative planning only works when participants have the authority to commit labour and sequence work. Planning sessions should be limited to trade foremen and crew leads who can make binding commitments for their scope.

Attendees who cannot commit resources or influence sequencing should be excluded. Last planners need to be involved from the first pull planning session and attend consistently across phase planning, lookahead planning, and weekly work planning to keep commitments credible.

This prevents unrealistic promises and protects the plan's credibility from the outset.

Practice 2: Use visual management to keep commitments visible

Maintain a shared planning board that shows task handoffs, constraints, and weekly commitments, using clear task states such as ready, in progress, complete, and blocked so status is unambiguous.

The plan must remain visible to all trades on site, not buried in scheduling software or reports. Visual management makes dependencies explicit, exposes problems early, and reduces miscommunication between trades and site leadership.

Practice 3: Add meeting cadence and accountability to contracts

Planning discipline weakens quickly when participation is optional. Define LPS requirements in subcontract agreements.

Set clear expectations for attendance at pull planning sessions, weekly planning meetings, and daily huddles. Require timely identification of constraints and active participation in PPC reviews so that responsibility is unambiguous and decision-makers are present when commitments are made.

Practice 4: Train teams and measure PPC without blame

Research from a number of Australian infrastructure projects suggested that training and organisational support are critical to successful LPS adoption.

A Victorian study examining digital LPS implementation on rail and road level crossing removal projects found that outcomes improved only when teams were trained, supported, and given clear ownership of the process.

In those projects, LPS delivered measurable improvements in schedule performance, cost control, safety, and quality. The common factor was not the tool. It was how well teams understood the system and how consistently it was applied.

Before rollout, align all participants on how LPS works and what is expected of them. PPC must be used to understand why commitments were missed, not who missed them. Variance analysis should focus on systemic issues such as design, procurement, access, or sequencing.

When teams trust that PPC is used for learning rather than blame, commitments become more honest, and problems surface earlier. That behaviour is what sustains reliability under delivery pressure.

Practice 5: Pilot one area and scale across phases

Start LPS in a defined area, such as a single floor, building, or work package, and track PPC trends and constraint reduction during the pilot.

Document lessons learnt and adjust processes before expanding across the project. Use measurable improvement to build buy-in from sceptical trades and reduce the risk of a full project rollout from day one.

The Last Planner System improves delivery reliability by turning plans into real commitments

The LPS gives construction teams a practical way to improve schedule reliability by releasing work only when it is ready and committed by the people delivering it. 

When applied with discipline, it reduces rework, limits programme volatility, and gives leaders earlier, more reliable insight into delivery risk.

Written by

Josh Krissansen

86 articles

Josh Krissansen is a freelance writer with two years of experience contributing to Procore's educational library. He specialises in transforming complex construction concepts into clear, actionable insights for professionals in the industry.

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