A New Zealand dairy equipment maker struggled with long lead times on stainless fittings every peak season. Three kaizen events in ten weeks cut lead time from 12 days to 5, raised weekly throughput by 44% and slashed overtime.
Key numbers
Every year, as the dairy season approached, a New Zealand dairy equipment manufacturer went through the same ordeal. Orders for stainless steel fittings surged, lead times stretched to 12 days, the workshop worked heavy overtime and customers waited. Everyone accepted it as the nature of a seasonal business.
The situation
The fabrication workshop cut, deburred, welded and finished a wide range of stainless fittings. Work moved between areas in batches, set-ups on welding fixtures were slow and varied between welders, and common fittings were made to order even though demand for them was predictable. Weekly throughput was around 310 units and overtime about 14% of hours.
What changed
Rather than one big project, the team ran three focused kaizen events over ten weeks, each tackling a different constraint, following the format described in what really happens in a kaizen event:
- Event one: the cutting and deburring area was rearranged for one-piece flow. Instead of cutting a full batch before deburring began, parts moved directly from saw to deburring station, removing queues and handling.
- Event two: welding fixtures were standardised, with common locating features and quick clamps, cutting set-up time between fitting types and making set-ups the same regardless of who did them.
- Event three: kanban was introduced for the most common fitting sizes, applying the approach in kanban for beginners, so standard items were replenished from a small stock while the workshop concentrated on custom work.
Each event involved welders, fabricators and supervisors from the workshop, and ideas from the workshop's idea system fed into the event scopes.
Results
Weekly throughput rose steadily after the first event, from about 305 units to 445, a 44% increase. Lead time fell from 12 days to five. Overtime dropped from 14% to 3% of hours, during the busiest part of the season.
Why three events worked better than one
Each event built on the last. Flow in cutting exposed the welding set-up constraint; faster set-ups made kanban for common sizes practical. Tackling them one at a time kept each event focused and achievable, and the results of the first built confidence for the next.
Lessons for your operation
- Seasonal peaks expose flow problems that exist all year.
- One-piece flow between adjacent processes removes queues quickly.
- Standard fixtures make set-ups faster and less dependent on individual skill.
- Use kanban for predictable items and free capacity for custom work.
- A series of focused events can achieve more than one large program.
