What a 3-week lookahead actually is
A 3-week lookahead (sometimes called a "short interval schedule" or SIS) is a rolling window cut out of the master CPM schedule and re-expressed in the language of the field: tasks small enough for a crew to finish in a day or two, with the constraints needed to start each one listed right next to it.
The window slides forward every week:
- Week −1 (last week): reviewed for actual vs planned, root-causes captured.
- Week 0 (this week): committed. Crews, materials, equipment locked.
- Week +1 and +2: planned. Long-lead items flagged, constraints being resolved.
From master Gantt to lookahead in five steps
- Pull the next 21 days of activities from the CPM schedule.
- Break each activity into daily tasks — "Drywall second floor" becomes "Hang rock — bedrooms 201–204 — Mon/Tue, 3-person crew".
- Add the seven constraints next to each task (see below). If a task can't pass the constraint check, it doesn't go on the committed week.
- Walk the crew leads through it in the weekly coordination meeting. They commit to week 0.
- Update the master schedule with anything the lookahead surfaced — slipped predecessors, missed inspections, material delays.
The seven constraints (the "can we actually start?" checklist)
Before a task is committable, all seven need a yes:
- Predecessor — is the work it depends on actually done?
- Materials — on site, staged, and the right quantity?
- Equipment — lift, hoist, pump, generator booked?
- Labor — crew assigned and confirmed by the foreman?
- Information — current drawings, RFIs answered, submittals approved?
- Permits / inspections — prior inspection signed off?
- Site / access — area cleared, safe, and accessible for this crew?
A task that fails any of these belongs on the planned weeks, not the committed week. Mixing the two is the single biggest reason lookaheads stop being trusted on a jobsite.
The weekly coordination meeting
Forty-five minutes. Same time every week. Everyone who runs a crew, plus the super and PM.
- Review last week — what was committed vs what got done. Percent Plan Complete (PPC).
- Root-cause every miss — one of the seven constraints, every time.
- Commit this week — each foreman commits to their crew's tasks out loud.
- Resolve constraints for week +1 and +2 — who's owning each one and by when.
- Update the master schedule with anything that moved.
PPC trending above 80% means the schedule is being run well. Below 60% means crews are being asked to start work that wasn't actually ready — fix the constraint discipline before adding more scope.
What good lookahead scheduling software looks like
- Generates the lookahead automatically from the master CPM schedule — no double-entry.
- Lets the foreman update task status from a phone, in the field, in two taps.
- Shows the seven constraints next to each task and won't let you "commit" a task with open ones.
- Recalculates the master Gantt the moment a lookahead task slips.
- Exports a printable weekly lookahead PDF for the trailer wall and the owner meeting.
How BuildPlan Pro handles the lookahead
BuildPlan Pro generates the 3-week window straight from the master CPM schedule, with the constraint checklist built into every task. Foremen update from the jobsite; the Gantt and the lookahead stay in sync automatically. 14-day free trial, no credit card required.
See the live demo · CPM scheduling explained · Generate a free starter schedule
Frequently asked questions
What is a 3-week lookahead schedule?
A rolling short-interval schedule that pulls the next 21 days of work out of the master CPM schedule and turns it into something a foreman can actually run a crew off of: who, what, where, when, and what's needed to start. Last week is reviewed, this week is committed, next two weeks are planned.
Why three weeks and not two or four?
Three weeks is long enough to catch material lead times, inspections, and predecessor slip — and short enough that the schedule still resembles reality. Two weeks misses procurement; four weeks fills with guesses.
Who runs the lookahead?
The site superintendent owns it. PMs feed it from the master schedule, foremen commit to the current week in the weekly coordination meeting, and the super updates the rollup before the next owner meeting.
How is a lookahead different from the master schedule?
The master Gantt models the whole job in activities and dependencies. The lookahead breaks those activities into the daily tasks a crew will actually execute, with constraints (materials, equipment, prereqs, inspections) called out next to each task.
What's the cheapest way to start?
A printed spreadsheet works for week one. Past that, you want the lookahead generated from the master schedule so a slip on Monday updates Friday's plan automatically. BuildPlan Pro does this — 14-day free trial, no credit card.