From Imperial Sugar News| June 16, 2010
by Gordon Curry/Newsroom Ink
Packaging Team Manager William McGhee receives a “statement of yield” every month, which tells him how much sugar the Port Wentworth refinery has produced and how much it should have produced – based on the raw sugar the refinery started with.
“You want the yield to be high,” says McGhee. The refinery always loses a very small amount during the production process, but McGhee’s aim is to package and make available for selling 99 percent of the original volume of raw sugar.
He suspected that two of the bagging machines – called FAWEMA #9 and FAWEMA #10, named after the manufacturer – were “giving away” sugar with each package and decreasing the yield. So, he had a DMAIC team do an analysis, starting with the FAWEMA #9 machine that typically packages 10-pound bags of extra-fine granulated sugar.
DMAIC – which stands for define, measure, analyze, improve and control – is a Six Sigma approach used to determine root causes of problems in manufacturing or other processes. In this instance, the team randomly pulled 100 bags off the line, weighed them and did some number-crunching.
What the team learned is that the average “giveaway” – or the average amount of extra sugar going into bags – was 45.2 grams per bag. That’s a giveaway of approximately 1 percent. “We saw an opportunity for improvement there,” says McGhee.
Overfilling packages decreases total plant yield. “If I produce five million pounds of sugar, I want 100 percent of that sugar to be sold at the maximum selling price. Overfilling bags means giving away product, which decreases our yield. ”
The DMAIC approach is particularly useful in a case like this because the analysis helps a business see what could be affecting yield. In measuring and taking stock of the process, says McGhee, “you’re trying to find out if you’re running your process in control, whether you’re staying close to what that target weight is.”
The team quickly did a DMAIC analysis to determine where on the FAWEMA #9 machine the company was losing time or incurring waste. Team members included Willie Jenkins, Willie Johnson, both FAWEMA operators; electrician Michael Anderson; mechanic Rodney Crutfield; and supervisor Tyrone Pinckney.
“Typically, what’s most hurtful to your process is lost time,” says McGhee. “Because if you’re not producing, you’re not making money.”
One of the big learnings can be seen in a Pareto chart that shows how much downtime FAWEMA #9 experienced. “We found that the biggest cause of downtime was operator breaks. So, we found a way to have someone else relieve those workers, and we immediately gained over an hour every day that we were losing to breaks,” McGhee points out.
The team also learned the equipment wasn’t running at the design rate. Every piece of equipment comes with an optimal running speed, which is based on the capability of all the parts. When FAWEMA installed the equipment, the company provided a design rate for it.
What happens over time, though, is that often when operators have minor problems on the line, they slow down the rate slightly – giving the equipment longer to a complete a cycle. Those minor adjustments add up, however.
By increasing the rate to bring it closer to its design rate, FAWEMA #9 went from packaging 10-pound bags of extra-fine granulated sugar at a rate of 40 bags per minute to 50 bags per minute.
“We gave ourselves the opportunity to produce 600 more bags every hour of the 10-pound bags,” McGhee says. “We built more capability into our hourly production rate just by increasing the speed.”
And while DMAIC teams typically do a fresh analysis with each piece of equipment or process, some of the learning from the FAWEMA analysis – such as the new approach to operators taking breaks – will translate to the FAWEMA #10 machine, as well as to the packaging process for different sized packages.
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