Title: DDGS Quality – Part 2: Are you in Control? How to Quantify Your Process with Control Charts Author
Submitted to: Distillers Grains Quarterly
Publication Type: Trade Journal
Publication Acceptance Date: December 2, 2007
Publication Date: March 1, 2008
Citation: Rosentrater, K.A. 2008. Ddgs quality – part 2: are you in control? how to quantify your process with control charts. Distillers Grains Quarterly. 4(1):24-29. Technical Abstract: As the fuel ethanol industry continues to grow, it will be increasingly important to produce high quality products, including distillers grains. One important way to do that is to reduce the variability in DDGS. This will not only help to ensure that customers' needs and expectations can be met, but it will also help to improve the reputation of the industry overall. In a previous article I discussed several issues related to DDGS quality, including general concepts of quality, types of variability, the need to quantify this variability, statistical thinking and its use in quality improvement. To improve DDGS by decreasing variability and increasing consistency, processes must be completely understood. The only real way to understand a process is to monitor it over time by measuring some quality characteristic. The goal of this article is to discuss the construction of run charts and quality control charts to help quantify DDGS production processes, which ultimately can help lead to reduced variability and better consistency. If a process is not in statistical control, then adjustments will need to be made to processing parameters, so that the process can become stable. What those changes are will depend upon the specific nature of the chemical constituents in the products, as well as equipment (type, condition, wear, etc.), standard operating procedures, and a whole host of other unique, site-specific variables. It will be up to operators to decide what are most influential to the final quality of their own DDGS. The ability of each plant to produce distillers grains with a high level of quality is critical to the continued success and future growth of the industry. Quality control and improvement techniques can help in this endeavor. And hopefully the tools discussed in this article can help.