The powder painting process for metal boxes and their components had the following issues:
- Required 3 shifts seven days per week and could not meet demand.
- Painting quality was poor, rework required sandblasting before painting a 2nd time
- Color change overs took more than 4 hours to complete
- Chemical spray treatment required hazardous waste removal weekly
The team applied Lean, Single Minute Exchange of Die (SMED), Quality Cost, Quality Function Deployment (QFD), and Design of Experiments (DOE) to solve the multiple issues within the Powder Painting Process.
- Value stream mapping identified the points of inventory build up, processing and cycle times, non-value adding activities, production scheduling issues, and processing bottlenecks.
- SMED was applied to color change overs to dramatically reduce the time.
- Quality costs were applied to build the business case and track the savings from the improvements.
- QFD was used fully understand customer requiremetns and to narrow the field of potential variation contributors in the overall process for optimal application of DOE.
- DOE was used to determine the optimal operating parameters for quality and efficiency of the powder painting process.
Solutions and Results:
The following solutions were implemented with associated results:
- A production scheduling system was implemented based upon due date and color of the components.
- The color change over process was re-designed and the time was reduced from over 4 hours per change to less than 30 minutes.
- The DOE resulted in defining the important process variables and their operating windows. The chemical spray treatment was eliminated and the hazardous waste removal cost. The paint line speed was increased for 3 feet per minute to 7.5 feet per minute (maximum line speed) and quality defects were virtually eliminated.
Overall results included a shift reduction from 3 down to 1 without overtime meeting all customer scheduling demands. Wasted paint was dramtically reduced. Total savings was $225,000 per month or $2,700,000 annual savings.