Six Sigma Students Uncover Ways to Cut Waste on Campus

Tuesday, September 15, 2015
Diane Evans teaching her students.

Gross data: Math students tackled the messy job of calculating food waste at Rose-Hulman as part of a Six Sigma sustainability project.

Pity the poor Six Sigma expert on "bring-your-child-to-work day." Imagine trying to explain your job when you spend each day analyzing a process, running mountains of data through statistical calisthenics, and then measuring sometimes tiny changes in output or efficiency.

Yet using Six Sigma, a well-known, statistics-heavy method for process improvement, means getting deep into the weeds of a problem with often exciting real-world results, as students of Rose-Hulman mathematics professor Diane Evans, Ph.D. have discovered. In the past two years, those students have used the Six Sigma process to improve sustainability on campus by cutting food waste and improving recycling. And, far from simply crunching numbers, they found themselves doing some pretty down-and-dirty real-world data collection.

To measure wasted food on campus, Evans' students scraped partially consumed hamburger buns, melted ice cream, and other uneaten goodies from students' dining trays into big plastic tubs for weighing. The next year, to collect recycling data, they fished through dozens of trash bags to determine how much plastic and other recyclable material was among the banana peels, coffee grounds, and pizza boxes inside.

"It was messy and it was tedious," Evans recalls.

In their first project, the students learned that a lot of food was being wasted. To change that, they launched a public education campaign, including posters and presentations in the dining hall. In the end, thanks to their efforts, the volume of tossed-out food was cut significantly. The students calculated that their campaign saved about 145 pounds of food per lunch period. Stretched over a year, that would save Rose-Hulman more than $33,000, they figured.

Last year, Evans' students increased recycling on campus using educational posters and adding to the number of recycling bins in the school's academic buildings. Using statistical analysis, they calculated their efforts reduced the percentage of recyclable material in the trash to below 20 percent, achieving their pre-project goal.

Diane Evans

Black Belt: Dr. Diane Evans, Ph.D., has been certified as a Six Sigma Black Belt twice. Her math students use the Six Sigma process to improve sustainability on campus.

Evans is a Six Sigma "black belt" twice over, meaning she has shown she has mastered the Six Sigma process and understands the sophisticated statistics behind it. She explains that the Six Sigma process is to 1) identify a problem, 2) collect data, 3) analyze the data, 4) recommend solutions and try them out, 5) measure the results, and 6) sustain the improvements into the future.

Six Sigma was developed at Motorola in the 1980s to reduce costly defects with their electronics, Evans notes. Since then, the method has become a standard in industry around the world.

This year, Evans' Six Sigma students will tackle a new problem: the high volume of paper towels used in Rose-Hulman bathrooms. If successful, they will once again use Six Sigma to eliminate waste and make their campus, and their world, a better and more sustainable place.

Note: Minitab, a maker of statistical software, has been following Evans' class projects on the company blog. She also authored the company's recently released core statistical concepts lesson plans.