When we first walked into the plant — 38,000 sqm, 110 machines, three shifts — the on-time delivery (OTD) rate sat at 71%. Eight weeks later it was 92%. Here is how, with as little hand-waving as we can manage.
Week 0: the diagnosis
We spent the first three days just walking the floor with the production manager. Three patterns jumped out. First, scheduling was done in Excel and propagated by Kakao screenshots — every change took 35-50 minutes to ripple through the plant. Second, machine downtime was tracked on paper and only entered into the ERP at end-of-shift, which meant root-cause analysis was always a day late. Third, customer due dates lived in a separate sales system that never talked to production.
Weeks 1-2: the data plumbing
We didn't change a single business process in the first two weeks. We just connected the data: every machine to LINKO Connect (Modbus + OPC-UA), every Kakao screenshot replaced with the work-order status board, every customer order ingested via the ERP webhook. The first big win was unintentional — once the production manager could see all 110 machines on one screen with live OEE, she identified two bottleneck cells nobody had noticed for years.
Weeks 3-5: replanning becomes a habit
We turned on the APS solver in advisory mode for two weeks — it suggested schedule changes but didn't apply them. Planners agreed with the suggestion 78% of the time, which gave them confidence to switch to auto-mode. From week 5 onward, every machine fault triggered a feasible replan within 3 seconds, and the planner only stepped in for the edge cases.
Weeks 6-8: the measurable wins
- OTD: 71% → 92% (+21 points). The CFO's #1 metric.
- Average changeover time: 47 min → 31 min (-34%). Driven by APS sequencing similar setups together.
- Planning headcount: 3 FTE → 1.5 FTE (others reassigned to quality engineering, not laid off).
- Audit prep time: 9 days → 4 hours, thanks to one-click traceability export.
What surprised us
The cultural change was bigger than the technical one. Once the production manager stopped being the human router for every Kakao message, she started spending two hours a day on continuous-improvement projects she had been postponing for years. The plant's first 5S Kaizen event in 18 months happened in week 7.
“We thought we were buying a scheduling tool. We ended up reclaiming our planners' brains.”