Six Sigma project reduces analytical errors in an automated lab

Medical Laboratory Observer, June, 2005 by Nancy Riebling, Laurel Tria

Controlling results

In the control phase, the Six Sigma team implemented a plan that incorporated individual and moving range charts for monitoring corrected results. The control plan enabled the team to determine the method for monitoring frequency, alert flag, action, and specific accountability for each of the key variables in the process. The DPMO for corrected results is now monitored on a monthly basis (see Figure 5). The Six Sigma metric has become part of the lab's quality-management program. Real-life examples of analyzer printouts and flag results are used to assess staff competency on an ongoing basis.

At the end of the control phase, the process went from a 4.8 sigma level to a 5.0 sigma level. Using the chi-square test, the team was able to demonstrate a statistically significant decrease in the number of corrected results. The technical area of the core lab has experienced a 20% growth in volume from the completion of the project in December 2003 to present. The Six Sigma team turned the project over to its process owner in January 2004. Since that point, the department has operated at a sigma level of 5.0 or higher and was at a 5.2 sigma level as of October 2004. This project produced no direct financial impact. As chairman of the Department of Laboratories, Dr. Thomas Sodeman observes, "The error-reduction project was undertaken because it was the right thing to do."

The Six Sigma DMAIC methodology has many advantages. It is a rigorous process that engages front-line employees in process redesign. It utilizes data and the voice of the customer to determine the factors that are most critical to quality. Controls and accountability are put in place to ensure the process remains efficient. Finally, this approach provides lab personnel with the tools to take a good process and make it even better.