Clean Room Staple Loading Kaizen Event
Kaizen Event – Medical Device Manufacturer
A full-service, vertically integrated FDA-certified medical contract manufacturer of finished assemblies, sub-assemblies, and precision components.
The company’s production of surgical stapler cartridges suffered from excessive lead times, poor flow and lower-than-expected volume. Approximately 200,000 parts per month were processed by two eight-hour shifts. Not including cleaning or product re-work time, it took employees 160 to 310 minutes to perform all major tasks in the production process. Before beginning the Kaizen event, the product’s annual average defect rate was 0.79%
To increase its annual production volume from 7.9 million to 8.5 million loaded staple cartridges without compromising safety or customer delivery schedules, the company retained Daniel Penn Associates (DPA) to lead a Kaizen event that would examine and streamline the company’s staple loading, validation, inspection, final assembly, and packaging processes.
The company wanted to reduce work-in-process inventory by 50%, improve process velocity by 10%, improve quality by reducing risk and reduce lead time to less than 10 days.
DPA Senior Consultant/Sensi Sal Santangelo began by training an eight-member employee Kaizen team within the staple cartridge production area. The team ‘learned how to see’ their work area in new ways that would help them gather observations and make valuable improvement recommendations.
- On Day One of the Kaizen event, the team created a data registry to capture current processes. They observed and documented production cycle times and counted work in process.
- On Day Two, the team created hour-by-hour work boards to calculate the number of stapler cartridges produced per hour per machine. After identifying the highest volume machine, they calculated takt time (the frequency at which a quality part must be produced to meet customer demand), work in progress and the level of parts at quality risk.
After value stream mapping the production area, the Kaizen team determined that too many inspections, too much handling and too much travel time between machines were causing the delays. The area lacked proper metrics to highlight and address production problems. Finally, the labor cost to re-work nonconforming materials was nearly equal to the selling price of the finished materials.
The Kaizen team mapped and tested a simplified one-piece flow design for the stapler cartridge molding/degating, staple loading, sterilization, packaging, and inspection areas. The design efficiently moved assemblies from the first molding process to loading and shipment of finished cartridges. By staging cartridges in porous baskets before and during cleanroom sterilization, and by improving the set up for final visual and video inspections, the team was able to eliminate several time-consuming touchpoints. By organizing the spray room and establishing new standard work norms, the team is increasing yields and reducing defects.
With no decrease in employees, the new staple loading cell design and the process has boosted throughput by 36% (from 2,200 to 3,000 assemblies per day), decreased material travel by 90% (from 4,200 to 390 feet), and decreased Work-In-Process At-Risk lead time by 43%.