Ask ten superintendents to explain the difference between their lookahead and their weekly work plan and you'll get ten different answers, most of them fuzzy. A lot of guys treat them as the same document at two zoom levels — the lookahead is just "the weekly plan but longer." That misunderstanding is exactly why so many jobs run a beautiful six-week lookahead and still blow their Friday commitments week after week.
The two documents do different jobs. The lookahead is where you get work ready. The weekly work plan is where crews promise to do the work that's now ready. One is a factory for removing obstacles; the other is a handshake. Once you see them that way, the whole planning system starts to click, and the failures start to make sense.
Two horizons, two jobs
The rolling lookahead typically runs three to six weeks out — I like six on a fast job, four on most things. Its purpose is not to tell anyone what to do next Tuesday. Its purpose is to look at everything coming down the pipe and ask, for each activity, "What would stop this from happening on the day we want it?" Missing submittals, material not on site, a prior trade not finished, an inspection not scheduled, an RFI still open, no crew available. Those are constraints, and the lookahead's whole reason for existing is to surface them early enough that somebody can clear them.
The weekly work plan has a much smaller job and a much higher bar. It covers the next five or six working days, and everything on it is supposed to be a genuine commitment — work that can be done because every constraint is already gone. The lookahead deals in "should"; the weekly plan deals in "will."
The link between them is the make-ready process. Work doesn't jump straight from a bar on the CPM schedule into a weekly commitment. It rides through the lookahead for a few weeks, getting its constraints knocked down one at a time, and only when it's genuinely clear does it earn a spot on the weekly plan. Skip that ride and you're just guessing on Monday and apologizing on Friday.
How an activity actually earns its place on the weekly plan
Here's the flow I walk trades through when I'm setting up the system on a new job. An activity enters the lookahead window — say it's five weeks out. It comes in "raw," with constraints attached. Over the next few weeks, in each planning meeting, we screen it: what's still in the way? Somebody owns each constraint and reports back. Submittal approved. Material confirmed on the delivery board. Layout done. Prior trade's inspection passed.
By the time that activity is one week out, it should be fully constraint-free — what the Last Planner folks call "sound." Only sound activities are eligible to become weekly commitments. That's the rule that separates a real planning system from a wish list. If you find yourself putting things on the weekly plan that still have open constraints, you don't have a weekly work plan — you have a to-do list with a due date, and it'll fail on schedule.
A good weekly commitment has three properties. It's constraint-free, so nothing outside the crew's control can stop it. It's right-sized — a crew can realistically finish it in the week with the labor they actually have, not the labor they wish they had. And it has a clear definition of done, so on Friday there's no arguing about whether it counted. "Rough-in the east wing" is not a commitment; "complete overhead plumbing rough-in and pass inspection, rooms 210 through 224" is.
Where this sits in the Last Planner System
If you've read anything about Last Planner, you know the four nested levels, but it's worth naming them because the lookahead-to-weekly handoff lives right in the middle:
- Master / phase schedule — the milestones. "Should" at the highest level. This is your pull plan, built backward from key dates with the trades in the room.
- Lookahead — the three-to-six-week make-ready window. Breaks phase work into real tasks and drives constraints to zero.
- Weekly work plan — the commitments. Only sound work makes it here.
- Daily coordination — the huddle where crews sort out the day's sequencing and hand-offs.
Each level feeds the next. The lookahead can't do its job if the phase plan is garbage, and the weekly plan can't do its job if the lookahead isn't actually clearing constraints. Most "planning" failures I see aren't weekly-plan failures at all — they're make-ready failures that don't show up until the commitment blows.
What actually goes wrong
The single most common mistake, by a mile: committing to work that was never made ready. A foreman shows up to the weekly meeting, feels the pressure to fill his row, and commits to hanging drywall in an area where the electrical rough hasn't been inspected. He knows it's shaky. He commits anyway because saying "not ready" feels like admitting failure. Thursday the inspector doesn't show, and the commitment dies. That's not bad luck — that was a constraint nobody cleared, dressed up as a plan.
Second: running the lookahead and the weekly plan as two disconnected documents. The scheduler keeps a lookahead in one file, the super runs the weekly meeting off a whiteboard or a separate spreadsheet, and the two never reconcile. Status from the field never flows back up to the lookahead, so the lookahead slowly drifts into fiction. When your planning tool ties them together — the near-term end of the lookahead is the source for the weekly plan, and Friday's completions update the lookahead — that drift disappears. This is one of the real reasons to run look-ahead scheduling in a single connected app like LookAheadWall rather than across three spreadsheets: the hand-off stops being a manual retype.
Third: overcommitting. New crews and eager foremen load up the weekly plan because it looks good in the meeting. Then reality — an absent crew member, a slow delivery, a rework surprise — eats the buffer and half the commitments fail. A plan you hit 70% of the time is worth more than a plan you hit 40% of the time, because the trades stacked behind you can actually rely on it.
Fourth: treating buffers as slack to be squeezed out. Between two trades that hand off to each other, leave a real gap. Frame-to-rough-in usually wants a day or two for cleanup, layout, and inspection before the next trade lands. If you butt every activity end-to-end on the weekly plan, one small slip cascades through every trade behind it. The lookahead is where you build those buffers in on purpose.
The weekly meeting is where it all connects
The weekly work planning meeting is the hinge between the two documents, and it has a rhythm worth respecting. Run it the same way every week:
- Score last week first. Go commitment by commitment: done or not done. No partial credit, no excuses yet. This is where you calculate PPC — Percent Plan Complete — the share of last week's commitments you actually finished. It's the single best health metric a job has.
- Analyze the misses. For every failed commitment, name the reason and, more importantly, the category: prerequisite work, materials, information/RFI, labor, equipment, weather, or changed conditions. The category is what you learn from.
- Review the lookahead. Walk the make-ready window. Which constraints got cleared this week? Which are stuck? Who owns the stuck ones and what's the date?
- Make next week's commitments. Only from the sound pile. Foremen commit for their own crews — not the super committing on their behalf. That distinction is the whole point; a commitment somebody else made for you isn't a commitment.
Notice that scoring comes before committing. When foremen know Friday's number gets read out loud in front of the other trades, the quality of Monday's commitments climbs fast. Nobody wants to be the row that always turns red.
PPC and variance: the part most jobs skip
PPC by itself is just a number. A job humming along at 55% and one at 85% both "have a PPC." The value is in the trend and in the variance reasons behind it. Track PPC weekly, and watch the reason categories pile up. If half your misses month after month are "prerequisite work not complete," your problem isn't the weekly plan at all — it's sequencing and make-ready in the lookahead. If they're mostly "materials," your problem is procurement and the delivery board. The failure reasons tell you exactly which upstream process to go fix.
This is the loop that actually makes a job get better instead of just busier: commit, measure, find the root cause, fix the process, commit again. A team that religiously runs that loop will pull its PPC from the 50s into the 80s over a few months, and the whole job feels calmer because the trades downstream can finally trust the plan.
The foreman and the sub are not spectators
None of this works if planning is something done to the trades instead of with them. The people who make the commitments have to be the people who do the work — that's the "last planner." A foreman who only shows up to receive marching orders will hedge, pad, and quietly plan around your schedule. Bring him into the lookahead: he's the one who knows his crew's real production rate and can spot a constraint you'd miss.
Same with your subs. Give them visibility into the lookahead so they can see their work coming and staff for it, and pull their foremen into the weekly commitment conversation so the promise comes from the trade actually holding the tools. A schedule you can hand to a sub's foreman — location-based, showing the trade-flow sequence and where his crew fits — turns "when do you need us" phone tag into a shared plan everybody already sees. That's the practical payoff of good short-interval scheduling: the coordination happens on the board, not in a scramble.
Bottom line
The lookahead makes work ready; the weekly work plan turns ready work into promises crews can keep. Keep the two connected, only commit to sound work, score your PPC honestly, and chase the variance reasons back upstream. Do that, and the endless Friday firefight starts to fade — not because the plan is perfect, but because you finally have a system that tells you the truth early enough to do something about it.