The Situation
During the period from January 2005 - June 2006, the basis weight or paper density had shifted on the Cream Face production line from 41 pounds per MSF (1,000 square feet) to 42 pounds. A corresponding trend had been noted on the Greyback production line as well. Quality rejects due to low tensile strength had increased over this same time period from zero (0) in January 2005 to one hundred sixty (160) tons during the months of May and June 2006. Operators were reacting to the lower tensile results by increasing the basis weight and adding long fiber to the feed. Strategic goals for Seven Hills Paperboard included the capability to produce both the Cream Face and Greyback products using 38 pounds per MSF, while maintaining the desired tensile strength.

The Response
Using the Lean Six Sigma DMAIC process, GENEDGE ALLIANCE assisted a Seven Hills Paperboard project team of employees through process improvement. GENEDGE ALLIANCE and the project team selected only those tools necessary to define, measure, analyze, improve and control how Seven Hills Paperboard manufactures its product and ultimately serves its customer. The project team benefited two-fold from these tools by first gaining a basic understanding of Lean Six Sigma techniques, and second, by applying a process for implementing the new changes necessary to drive continuous improvement. Laura Rathburn, Team Leader and Blackbelt for GENEDGE ALLIANCE, partnered with Seven Hills Paperboard's Greenbelt Scott Palmer to lead the project team whose end focus was to reduce basis weight.

Together they led the project team, sponsored by Seven Hill’s General Manager Ed Melton, as they pursued the following approach in achieving their objectives:

• Assisted in the facilitation of a Seven Hills Paperboard project team on a Lean Six Sigma project utilizing the DMAIC phases;
• Trained the project team on how to use Kaizen Design of Experiments (KDOE);
• Provided each team member with instruction on the KDOE technique, coaching on how to perform the technique with student materials for future reference;
• Trained the team to perform a KDOE utilizing the following steps:
  • Identify the project area and develop the project charter
  • Develop a flow chart of the project area
  • Construct a Cause & Effect Diagram
  • Rank and select factors
  • Develop the design matrix
  • Coordinate data collection
  • Analyze the data and make conclusions
  • Review results with team
  • Develop an implementation plan
  • Establish needed controls
• Led the team through a KDOE to identify major interactions of the Pulping Process as they related to Machine Direction Tensile Strength;
  Assisted in the facilitation of the team through several other KDOE’s to identify process parameters that could affect MD Tensile Strength as they related to the drying and sheeting processes.

The Results

• During the period from December 2006 - April 2007, eight (8) separate KDOE’s were conducted. The test factors were selected from the Cause & Effect Diagram using the multi-voting selection technique. All tests were designed as two-level, full factorial, with two to four test factors per test. Results were compiled for each of the main effects as well as any potential interactions between test factors, and were displayed manually via graphs for interpretation by the project team. These same results were interpreted using Minitab software to validate and compare the results between experiments. A summary of those factors affecting tensile as shown by the test results was provided to Seven Hills Paperboard's management.
• In addition to understanding which variables most affect MD Tensile strength, there were many lessons learned as a result of these experiments. This knowledge gained was summarized in a final report to management and later implemented resulting in overall process improvements within the facility.
• Manufacturing Centerlines were established for each of the critical process variables based on the knowledge gained through the experiments. Additionally, a Process Control Plan was developed by the project team with a full implementation plan established. Corresponding Standard Operating Procedures (SOP) were drafted for several key functions affecting process control.
• The annual financial impact from this project is estimated to be $1,800,000.
  

Management's Comment
"Everything about the project exceeded my expectations. Not only did we get the results we were looking for, but more satisfying to me was the enthusiasm and interest shown by the team members throughout the course of the project. Their willingness to learn a new way of doing things and accept the results was key to implementing the needed changes." - Ed Melton, General Manager

View their site!