The Last Planner System Without the Jargon

Lean Construction has a vocabulary problem. Foremen do not want to hear about 'reliable promising' at 6:45am. They want to know what they are building this week and what is in their way. Strip the Last Planner System (LPS) back to its bones and it is just a weekly discipline for answering those two questions with the people who actually do the work.

There are four conversations. The master schedule is what the project should achieve. The phase plan, built collaboratively backwards from a milestone, is what the team will achieve. The make-ready look-ahead, usually six weeks, is what the team can achieve once constraints are cleared. The weekly work plan, signed off Friday for the following week, is what the team commits to deliver. The final conversation — what was actually done — is the feedback loop that makes the whole system improve.

Pull planning is the part most teams skip and then wonder why LPS is not sticking. Get the trade foremen together with sticky notes, work backwards from a hard milestone (a slab pour, a roof watertight date, a service-cutover deadline), and let them negotiate sequence and duration. The plan that comes out of the room is owned by the trades because they built it. The plan that comes out of the planner's office is not.

Make-ready is where the system pays for itself. Every week the look-ahead is reviewed and the constraints on the upcoming activities are made explicit: design information, materials, plant, prerequisite work, permits, inspections. Every constraint has a name and a date. The job of the make-ready meeting is to clear those constraints before the activity reaches the weekly work plan. If you cannot clear them in time, the activity does not get promised.

The metric that matters is Percent Plan Complete (PPC) — of the commitments made last week, how many were delivered. Anything above 80% on a complex job is a healthy team. Below 60% and you have a make-ready problem, not a productivity problem. The trap is to chase PPC as a number; the value of PPC is the conversation it triggers about reasons for non-completion. Tag every miss with a root cause — prerequisite work late, materials, weather, design, capacity, change — and the patterns become obvious by week six.

Roll-out on a live project takes about ten weeks. Week one is the pull plan for the next phase. Weeks two and three are the first make-ready cycles and the first weekly work plans. Weeks four to eight are when PPC is unstable and reasons for non-completion are noisy; resist the temptation to abandon. By week ten the cadence settles and the foremen stop calling it 'that lean thing'.

Common pitfalls. Senior management treating LPS as a foreman ritual they do not need to attend — it dies the moment that signal is given. Plan boards in the site office instead of where the work is done. PPC reported up the chain as a KPI rather than used by the team as a learning signal. And the perennial favourite: a planner who silently rewrites the weekly work plan when commitments slip, hiding the data the system needs to improve.

Start with one trade and one phase. Run a 90-minute pull planning session, write commitments on sticky notes, and meet for 15 minutes every morning to confirm them. Within four weeks PPC will move, the foremen will stop calling it 'that lean thing', and the conversation in the site office will shift from blame to constraints. That shift is the whole point.