Kellogg$$s Cereal Production Process

John A$.$ Bryant, chief executive officer of Kellogg Company, scans the production reports lying on his new desk in the company$$s corporate headquarters in Battle Creek, Michigan. On January $2,2011,$ Bryant had been named CEO of Kellogg, which produced $$12\mathrm{.}4$ billion in net sales worldwide, making it one of the largest cereal companies in the world$\mathrm{.}1$ Though he has years of industry experience, Bryant is trying to gain a detailed understanding of the company$$s cereal production process in preparation for his meeting with the board of directors the following week.

One issue in particular concerns him. In the reports from various factories, he is finding an issue with inefficient production flows for the popular Raisin Bran and Frosted Flakes cereals. Bryant has hired a consultant to investigate the root cause of the production line$$s inefficiency, and the consultant has concluded that the packaging lines sometimes are being starved of cereal. This inefficiency in the cereal production process is costing the Kellogg Company thousands of dollars every day in lost revenue. The board of directors will surely bring up this topic, so Bryant knows that he must create a viable solution before his meeting with the board next week.

The consultant knows that the key to streamlining the factories$$ troubled production process is to determine the optimal number of hours that one brand of cereal should be run before switching to another brand. Bryant knows that if the consultant can determine this figure, Bryant will be able to ensure a smooth, uninterrupted flow of delicious cereal coming from his factories.

Birth of the Kellogg Company

The cereal industry in the US has its roots in the practices and values of the early American $7$th Day Adventists. In $1866,$ the Adventists founded the Battle Creek Sanitarium, a hospital and health spa, where wealthy patients were fed a steady vegetarian diet, including many grain$-$based foods$\mathrm{.}2$ One of these was the wheat flake, an invention of the superintendent, Dr$.$ John Harvey Kellogg. In $1906,$ Dr$.$ Kellogg$$s brother, William Keith Kellogg, noticed that these flakes were gaining popularity among the sanitarium$$s guests, prompting him to build the first flakes factory to serve the growing demand$\mathrm{.}3$ This factory would later serve as the foundation for the Kellogg Company$$s international operations.

Published by WDI Publishing, a division of the William Davidson Institute $($WDI$)$ at the University of Michigan.

$2011$ William Davidson Institute. Research Associates John L$.$ Parker and Nilima Achwal developed this exercise under the supervision of Professor Izak Duenyas, the John Psarouthakis Professor of Manufacturing Management at the University of Michigan$$s Ross School of Business.

From its first $44$ employees in Battle Creek in $1906,$ Kellogg grew to $31,000$ employees in $18$ countries by $2010,4$ manufacturing over $1\mathrm{.}7$ billion pounds of food in its Morning Food manufacturing facilities alone. The Kellogg brand was a recognized name in $180$ countries, becoming the highest$-$ranking global brand among packaged food manufacturers. International cereal and snack brands accounted for more than a quarter of its $$12\mathrm{.}4$ billion in net sales in $2010\mathrm{.}5$

Besides the cereal line Kellogg$$s$,$ Kellogg Company touted many other popular brands, including Keebler, Eggo, Cheez$-$It$,$ Nutri$-$Grain, Famous Amos, Morningstar Farm, and healthy snack line Kashi$\mathrm{.}6$ Some brands were almost ubiquitous in the US; in $2010,$ two out of every three US families with children consumed Pop$-$ Tarts$\mathrm{.}7$ Throughout the years, Kellogg Company sought to stay true to its core values of nutrition, health, and quality, set down by its founder William Keith Kellogg over a century ago.

Kellogg$$s Cereal Production Process

The Kellogg$$s cereal production process used one cereal line to process two brands of cereal: wheat$-$ based Raisin Bran and corn$-$based Frosted Flakes. The line processed cereal in two stages: flake prepping and cooking$-$packaging.

Stage $1$: Flake Prepping

The flake prepping stage began when raw corn grains or wheat flakes, depending on the cereal, entered a large, rotating pressure cooker, which used a screw to grind the raw materials into a flaky mash. Next, the mash entered a drying oven to remove excess moisture. Large, metal rollers then crushed the mash into thin flakes, which were ready for the cooking$-$packaging stage. The steps for stage one can be seen in Figure $1.$

Figure $1$

Stage $1$: Flake Prepping

Source: Made How

$2$

Stage $2$: Cooking$-$Packaging

In the cooking$-$packaging phase, the prepped flakes entered a cereal cooker, at a rate of four tons of cereal per hour, where they were baked until turning golden$-$brown. Next, the baked flakes entered a coating drum that sprayed sugar and vitamins onto the flakes; the coating drum could process four tons of cereal per hour$\mathrm{.}8$

Depending on which brand of cereal was being run, the cereal flakes entere