Precision-Machining Plant
Customer PPM down 51% · audit prep from 2 days to 2 hours
The starting point
The plant supplies machined housings to European Tier-1s and is audited constantly — ISO 9001 surveillance, customer process audits, and an aerospace prospect's AS9100 gap assessment on the calendar. The quality system itself was solid; the evidence was the problem. Inspection records lived in four spreadsheets, calibration certificates in a shared drive, and shift checklists on paper that took two days to assemble before every audit.
Worse, the spreadsheets couldn't prove integrity. When a customer quality engineer asked 'how do I know this record wasn't edited after the fact?', the honest answer was: you don't. That question cost the plant a contract shortlist in 2025.
What changed, step by step
LeanOS runs one connected loop — audit → defect → fix → root cause → kaizen → standard → recognition. Here is what each step did at this plant.
Layered process audits on a cadence that keeps itself
The plant used LeanOS walks not just for 5S but as layered process audits: team leads walk daily, area managers weekly, the plant director monthly — each on their own checklist, each from a phone. The system chases the walker, not the other way round: coverage is visible per zone per layer, and a missed walk shows up red on Monday.
Findings stopped dissolving into email
Every audit finding, machine anomaly, and customer complaint now lands on one defect board with an owner and severity. The AI clusters repeats — it flagged that three 'different' burr complaints across two months were all the same deburring station, which no spreadsheet had connected.
Countermeasures with proof, not promises
Closure requires an after-photo and a second signature — performed-by and verified-by are different people, enforced by the system. The AI drafts the fix-plan from the finding photo and the machine's history, and the quality manager edits rather than writes. Average time from finding to verified closure fell from 23 days to 6.
The burr problem got a proper A3
The clustered deburring findings became an A3. The fishbone pointed at Machine and Method; the 5-Why thread ended at a worn fixture that operators had been compensating for by hand. The countermeasure — a fixture replacement schedule tied to cycle count, not calendar — was verified over six weeks of PPM data. Customer PPM on that part family dropped 51%.
Improvements with a euro sign attached
Setup-time kaizens on the 5-axis cells, a tooling-reuse program, and the audit-prep time itself all went through the kaizen ledger with finance verification. The verified total reached €180,000 a year — and because every kaizen links back to the defect or A3 that triggered it, the plant can show an auditor the full chain from finding to saving.
Evidence the auditor can click through
This is where LeanOS earned its keep: the audit log is SHA-256 hash-chained, so any after-the-fact edit breaks the chain visibly. Calibration certificates live on each gauge with validity gates — a checklist simply refuses a reading from an out-of-cal instrument. At the last ISO surveillance, the auditor sampled twelve records in the morning and was done; prep had taken two hours, not two days.
Quality culture you can see moving
Near-miss reporting — historically a form nobody filed — quadrupled once logging one took thirty seconds and earned points. The monthly quality round now starts with the leaderboard and the trend wall. It is a quieter kind of morale than a podium ceremony, but participation in layered audits sits at 96% and has stayed there.
The results — safety, quality, delivery, cost, morale
Thirty-second phone capture plus leaderboard points took near-miss reporting from 3 a month to 13 — the leading indicator the safety board had wanted for years.
The deburring A3 and cycle-based fixture maintenance halved PPM on the affected part family.
Faster closure of machine anomalies and fewer quality holds lifted on-time-in-full to 99%.
Setup-time reduction, tooling reuse, and reclaimed audit-prep hours, all finance-verified in the kaizen ledger.
The quality team got its week back before every audit — and 96% sustained participation in layered walks.
“An auditor asked how he could trust a record hadn't been edited. I showed him the hash chain and the dual signatures. That conversation used to take two days of preparation; now it takes one click.”
Illustrative deployment story: a composite of typical LeanOS rollouts; company and names are fictional.