Skip to main content


Butler, Indiana

Midwest manufacturer Therma-Tru captured the attention of competitors 25 years ago when it introduced an entryway door that looked as beautiful as wood and outperformed the durability of steel.


To cut costs, bolster production, streamline processes and establish metrics to gauge improvement, Therma-Tru partnered with Purdue University's Manufacturing Extension Partnership (MEP). Purdue had worked closely with Matt Kramer, Therma-Tru's Continuous Improvement Manager and a member of TAP's Advisory Committee for the Northeast Indiana Advanced Manufacturing (Lean) Network.


Building on that relationship, Therma-Tru took this message to all its Butler employees. More than 30 engineers and support personnel have been formally trained in Six Sigma and Lean Manufacturing concepts. And efforts are under way to expand that to more Therma-Tru employees.


The results have been significant and immediate:

  • To address a defect problem that had hampered production for more than a decade, Therma-Tru adopted a new measurement system using Gage Repeatability and Reproducibility, or R+R, methods. The defect was reduced by 95 percent in the first two years, with annual savings exceeding $100,000.
  • Therma-Tru cut by 50 percent the rate of returned doors, known as Return Goods Authorization, or RGAs. Officials say savings in labor and product costs from this effort have been substantial.
  • To pinpoint the cause of a variation in cycle times for two molding presses, Therma-Tru implemented a new standardized process that is regularly audited. As a result, cycle times were reduced by 25 percent. And the process will be rolled out to Therma-Tru's other 22 presses over the next few years.
  • By streamlining production and minimizing variability across its lines, variation has been reduced and productivity continues to climb. The plant has increased capacity by nearly 30 percent over the last two years.

The partnership between Purdue's Manufacturing Extension Partnership and Therma-Tru has sparked a complete mindset change among all 700 associates at our Butler facility. Through this team-focused training in Six Sigma and Lean Manufacturing concepts, Therma-Tru is better positioned for growth. We are already seeing significant improvement on our bottom line and a better product for our customers.” 

- John Clarke, Director of Corporate Quality, Therma-Tru

Download PDF
Return to main content

Purdue Manufacturing Extension Partnership, 550 Congressional Blvd., Suite 140, Carmel, IN 46032, (317) 275-6810

© 2024 Purdue University | An equal access/equal opportunity university | Copyright Complaints | Maintained by Manufacturing Extension Partnership

Trouble with this page? Disability-related accessibility issue? Please contact Manufacturing Extension Partnership at