Lookahead Planning in Construction
Lookahead planning is the step in the Last Planner System that stands between the master schedule and the weekly commitments. Every activity in the next six weeks is screened for constraints, each constraint is given an owner and a date, and only activities that are genuinely constraint-free are allowed to reach the committing week. It is the single most under-practised step in lean construction — and the one that explains most PPC underperformance when it is skipped.
What is lookahead planning?
Lookahead planning is the Last Planner System screening step that takes the master-schedule activities inside a rolling six-week horizon, tests each for the eight standard constraint categories, assigns owners and dates for clearing each constraint, and promotes only constraint-free activities into the weekly commitment plan.
Also known as: make-ready planning, screening and pulling, six-week lookahead, phase lookahead. The horizon varies — four weeks is common on fast-cycle fit-out, eight weeks on infrastructure — but “six-week lookahead” is the default in most LPS literature.
The lookahead process, step by step
Lookahead is run as a short weekly meeting — 30 to 60 minutes — with the main-contractor planner, the last planners for the trades inside the window, and anyone who owns constraints that need to be cleared. The output is not a report; it is a filtered list of activities that have been pulled into the next few weeks because they are ready, and an owned action list for everything that is not.
- 1
Pull the window from the master
Export the activities starting in the next six weeks from the CPM master. These are the candidates for commitment. In a healthy lean programme the master is already up to date; in most programmes this step surfaces the first problem — the master is weeks out of sync with the site.
- 2
Screen every activity against the eight constraints
For each activity, test: design, materials, labour, equipment, prerequisites, permits, access, safety. Any activity with an open constraint is flagged. The purpose is not to blame; it is to make the constraint visible before the week it would silently kill the commitment.
- 3
Assign owners and dates to each open constraint
Every open constraint gets a name and a date. “MEP coordination model behind by two weeks” is a status; “Rajiv to re-issue coordinated model by Friday close, escalate to design manager Monday if not received” is make-ready.
- 4
Pull work only when constraint-free
Activities that enter the two-weeks-out window must be clean of open constraints. Anything still constrained at the two-week line is either resolved immediately or pulled out of the plan and rescheduled. This is the step most teams skip — and it is why PPC stays below 60%.
- 5
Promote to the weekly commitment plan
Constraint-free activities become the input to the weekly commitment conversation. Last planners commit from this filtered set, not from the master. The weekly meeting then becomes a reliable-promise conversation instead of a status update.
- 6
Feed reason-code trends back in
Each week the previous week's PPC and reason codes are reviewed in the lookahead meeting. If “materials” is the top reason three weeks running, the next lookahead gives materials-related constraints an earlier screen date. This is what turns the lookahead into a learning instrument.
The eight standard constraint categories
Most mature LPS implementations screen against the same eight categories. A ninth project-specific category is common on sectors with heavy commissioning or environmental compliance.
Design
Drawings issued, RFIs closed, submittals approved, coordination model up to date.
Materials
Procured, on order, delivered to site, stored in the right staging area.
Labour
Crew available, correct trades, certifications current, inductions complete.
Equipment
Plant on site, inspection in date, consumables stocked, fuel and lifting plans in place.
Prerequisites
Upstream trade complete to the agreed handoff condition, inspections signed off.
Permits & inspections
Statutory permits held, hot-work and confined-space permits raised, inspector availability booked.
Access
Area cleared, lifts and hoists booked, lay-down space allocated, services isolated if needed.
Safety
Method statement issued, risk assessment signed, exclusion zones agreed, PPE and rescue plans in place.
Worked example: a Thursday lookahead on a residential block
Thursday morning on a 14-storey residential project. The lookahead meeting covers activities starting weeks three through six. The constraint register below shows what the screen surfaced and how make-ready assignments were made.
| Activity | Starts | Open constraint | Make-ready action |
|---|---|---|---|
| Curtain wall, level 7 | Wk 3 | Materials — second shipment delayed | Logistics to confirm new ETA by Monday; raise alternate if slip > 5 days |
| MEP first-fix, levels 5–6 | Wk 3 | Design — RFI 142 open on riser routing | Design manager to close RFI by Friday 17:00 |
| Partition boarding, level 4 | Wk 4 | Prerequisite — concrete slab inspection outstanding | Inspector slot booked Tuesday; concreter to clear slab Monday |
| Facade install, levels 7–9 | Wk 4 | Access — mast climber permit renewal | H&S to lodge renewal by Thursday; backup rigging plan prepared |
| Snagging, level 3 | Wk 5 | Prerequisite — painter second coat not scheduled | Painter to confirm commitment at next weekly meeting |
| Lift testing, cores A–B | Wk 6 | Permits — commissioning engineer unassigned | Vendor to nominate engineer by end of this week |
What the lookahead did for next week's commitment
Of six activities screened, two were cleared in the meeting itself (RFI 142 by Friday, inspector slot Tuesday). Three had owned make-ready actions with dates. One — the curtain wall shipment — was flagged as a potential two-week delay that needed an alternate. None entered the next weekly commitment plan without the constraint being closed or an alternate agreed. The Friday committing meeting took 20 minutes instead of its usual 50, because the screening work was done.
Where lookahead planning fails
Lookahead is the LPS step that most often exists on paper but not in practice. The template is in the project handbook; the actual screening does not happen or stops after week six.
Constraints logged but never worked
The spreadsheet has an “open constraints” column that accumulates entries week over week and never clears. Make-ready has become a diary, not an action list. The giveaway: no owner, no date, no escalation path.
Lookahead is a status update, not a screen
The meeting walks through the next six weeks reporting what each trade will be doing. That is a Gantt review, not a lookahead. The lookahead question is “what has to be true for this activity to actually start?” — and if the answer is not confirmed, the activity is not allowed to commit.
No reason-code feedback loop
PPC is calculated weekly but the reason-code trend never changes the lookahead horizon or the screening priority. “Materials” shows up as the top reason for ten weeks straight and the materials screen still happens at the same time it always did.
Lookahead drifts from the master
The lookahead spreadsheet is maintained by the project planner; the master lives in P6 and is updated by someone else. By week three they tell different stories. This is the failure mode that drives most LPS pilots to stall.
How VisiLean runs lookahead on top of a live CPM
Lookahead is a view of the master schedule in VisiLean Planner, not a separate spreadsheet. The screening work is done against real CPM activity IDs, so make-ready decisions immediately affect what the committing week pulls from.
- The lookahead window is a filter on the master schedule, so the screening work and the weekly commitment conversation run against the same source of truth — no re-exporting into a separate spreadsheet.
- Constraints are mapped against the master schedule, with owners, dates and escalation notes captured on the activity itself.
- Make-ready updates and progress flow between the office and the field via LiveSite, VisiLean's mobile app — the same app the last planners use to update completion.
- Reason-code trends from the previous week's PPC are visible to the team as the lookahead meeting opens, so the screening priority can adjust to what is actually breaking.
- Weekly commitment conversations work from the filtered constraint-free set, keeping the plan aligned with what the trades say is actually ready.
Related methods
Last Planner System
The production-control system the lookahead sits inside. The five conversations, PPC calculation, and how lookahead feeds the weekly commitment.
Read morePull Planning
The reverse-pass session that produces the sequence the lookahead then screens. Pull decides what order; lookahead decides whether it is ready.
Read morePPC — Percent Plan Complete
The reliability metric. Lookahead failures show up as low PPC — the sign that constraint screening is not actually happening.
Read moreVisiLean Planner
The product that runs the master, the lookahead and the weekly commitments as three views of the same schedule.
Read moreFrequently asked questions
What is lookahead planning?
Lookahead planning is the Last Planner System step that screens every upcoming activity for constraints — design, materials, labour, equipment, prerequisites, permits, access, safety — before the activity is allowed into the weekly commitment plan. The usual horizon is six weeks, which gives enough runway to clear most constraints but is short enough that commitments remain realistic.
How is lookahead planning different from the master schedule?
The master schedule (usually a CPM in Primavera P6, Microsoft Project or Asta Powerproject) says what should happen. The lookahead says what can happen — which upcoming activities are actually constraint-free and therefore safe to commit. The master drives the lookahead window; the lookahead filters what reaches the weekly work plan. Both are needed; one does not replace the other.
What is make-ready planning?
Make-ready planning is the active half of the lookahead process. It is not just identifying constraints — it is the explicit assignment of actions and owners to clear each one in time. “Submittals not back by Thursday” is a constraint; “Priya to chase the architect by Monday close, escalate to the PM Wednesday if no response” is make-ready. The LPS literature calls these two steps screening and pulling, and the discipline is to do both every week.
What are the standard lookahead constraint categories?
Most LPS implementations use eight: design (drawings, RFIs, submittals), materials (procurement, delivery, site storage), labour (crews, skills, certifications), equipment (plant, tools, inspection), prerequisites (upstream trade completion), permits and inspections, access (areas, lifts, lay-down space), and safety (method statements, risk assessments, exclusion zones). Any constraint that does not fit one of these is usually a project-specific category — for example commissioning or environmental on data-centre and infrastructure jobs.
What makes a lookahead process fail?
The usual failure mode is that the lookahead is maintained in a weekly spreadsheet that nobody updates between meetings. Constraints get captured but not actively worked, no one owns clearing them, and the sheet goes stale by week two. The second failure mode is treating the lookahead as a status update instead of a screening step — a week has not been well-planned if every activity in it is still constrained.
See a lookahead running against a live CPM master
VisiLean treats the lookahead as a filter on the master schedule — constraints, owners and clearing dates live on the activities themselves, not in a side spreadsheet.