I — Datum

II — Conditions

The plant was absorbing demand from M&A activity and organic growth. It had kept a consistent schedule of procuring the newest Heidelberg presses, but a mix shift toward smaller jobs moved the constraint downstream: Polar AutoCut finishing lines could not change over fast enough to keep pace with the press fleet.

III — Measured

Twelve minutes looked like the result. It was holding the real constraint, which sat downstream of the cutter and never appeared as a queue.

IV — How it was found

The cutting lines were inflating changeover times to accommodate downstream packers, whose own changeovers ran 12–14 minutes. That wait was being recorded as cutter internal time, so it never appeared as a queue and no stopwatch on the cutter would find it. Twelve minutes was not the cutter’s speed; it was the packers’.

A painted Mylar block on a bull clip, hung to indicate 20 minutes remaining on a job, let the cutters signal an impending changeover in advance. Packers made boxes and set up sortation lines before the stop. With that burden external, the first setup measured 4.8 seconds of internal time. The blocks were completed 2 January 2020.

The tooling and motion work bought 27 minutes down to 12. The remaining burden was a scheduling signal costing a sheet of Mylar and a bull clip.

V — What it released

With finishing no longer the constraint, the Polar lines pulled through at press pace. The Speedmaster ran 18,000 sheets per hour sustained. The plant absorbed over 30% demand growth with no added labour — zero temporary staff, zero new hires. The world impression record on that press followed.

VI — Stated conservatively, on one line

The labour figure counts one line and excludes the throughput it released, which is where the value was. Setup counts of four to five per shift, two shifts, seven days.