01 October 2004
What's brewing in the plant?
South African plants make headway in revamping process.
By Ellen Fussell
When it's Miller time, you want to know you can go to the establishment of your choice and get the same taste sip after sip. And you want to make sure a brew tastes the same, whether you're in Milwaukee, London, or South Africa. That's why it's important to build consistency and interoperability into the brewing process. Knowing those key elements led SAB Ltd., the South African division of SABMiller plc, to begin incorporating a new software system suite of products within its South African plants.
The problem? The company had originally been operating from a SCADA system, under separate islands of automation. Some of the older breweries made use of control stations, which were very area specific. SCADA systems historically operated from a design for single station or smaller operations environments. With the old SCADA system, "an operator may not readily be able to view the entire plant from a single location," said Mike le Plastrier, director of Futuristix, a distributor of industrial automation products in South Africa.
The impetus for change came when the company realized engineers would need stronger process knowledge and production experience to maintain the brewing standards SAB was used to working with. "The newer plants require the operators to be multiskilled. They need to run the brewery and ensure high uptime," le Plastrier said. "They need strong process knowledge as well as production experience." Making the process more consistent would help brewers build on their quality brewing processes.
The solution was a universal workstation that incorporated a set of different software components running in combination, but the operator simply works from one workstation, which controls the entire plant. It's a single galaxy across a whole operating plant that lends itself to more efficient collaboration across the manufacturing environment and improves efficiency. "This workstation is a key concept in that it ensures every workstation in the plant is able to work in the same way and provide the same information," le Plastrier said. "Thus the operator can view and control any section of the plant from any workstation—he is not area bound."
Interoperability is key
The ability to make all plants interoperable was a key component in making the decision to switch to the new process. Thinus van Schoor, SAB's automation manager, said interoperability had been a challenge before because of the variety of platforms the company used in each plant. "The systems needed to have migration ability to integrate to each other and to the information systems on top to make the processes more efficient throughout the South African plants," he said.
The workstation gives engineers an integrated view of operations of the business, management, and process control levels. "Before we started using the systems here at the training institute, each plant had its own system, and you couldn't go from one brewery into another and just take up the reins," said Midrand Training Institute brewer Andrew Downes. "You had to learn their SCADA system, their interface, before you could operate the plant. With the new system, you can go from one plant to another and everything looks and feels the same."
Key components, single solution
While the setup operates under a concept of singularity in the foreground, in the background these components do have specific, distinctive tasks. The batch application schedules and runs every batch of beer in the plant and provides a record of each batch. It ensures that operators execute the batch correctly, with the correct ingredients, and to the correct quality specifications.
The manufacturing execution system (MES) is a set of graphical application development tools helping track batch record quality throughout the plant. It works with enterprise resource planning and supply chain management systems to provide real-time event data and to notify the internal and external value chain about the factory floor's activities. Genealogical records provide a complete history of materials consumed during a product's manufacturing process.
The production data historian forms the backbone of the process—continuously logging all activities. "This forms the plantwide historian database for us to review actions taken, to graph temperature profiles, and to review the status of any apparatus over time," le Plastrier said.
No more redundancy
SAB also faced another challenge. A diverse spread of manufacturing operations and market demands existed, along with varying degrees of existing automation and control system hardware platforms and software environments. They needed a way to easily roll over changes and updates, over one network, so they wouldn't have to go to each individual plant when a change ensued.
The solution? In addition to its new process, the company added a pilot program at the South African training institute in Midrand, where they began using a baseline framework. The new platform allows each plant to share objects from code, building like systems for other plants, without reprogramming the system every time. The new architecture is "like a circuit board you can plug things into," le Plastrier said. "There's no more integration because it's fundamental to the whole design. With this base in mind, you can now use any components, and it all works together automatically."
"The chain of events that would enable us to meet these challenges started with the implementation of Ibahyi brewery in 2000," said van Schoor. " Ibahyi would become our blueprint for excellence." At the Ibahyi brewery, SAB wanted convenience, so the brewery took advantage of all production software coming from one vendor. They spent significant up-front design time to ensure they could provide a single interface to the user for all the software and to ensure he would, at all times, be able to have a plantwide view of operations if he needed it.
Once they found it to be working well and they approved the standards, SAB took the process into the Prospecton, South Africa, brewery for its first large-scale implementation. SAB's update of the Prospecton brewery made use of the updating architecture to provide a common framework across the site "not only for SCADA plant control and operations, but also for SAB's developing MES requirements," le Plastrier said. From there, it has been rolled out to other South African breweries (Rosslyn and Pholokwane), and an extension is coming down the pike for Prospecton and the Newlands brewery in Cape Town.
One result? With the new platform at the Rosslyn plant, it took them two weeks to implement the process compared to what should take months. "Sure, it saves time," le Plastrier said, "but even more important, it creates standards, which means the engineer can visit any of the breweries and they all work the same. The process looks exactly the same in Johannesburg and China."
The brewing process: a primer
The brewing process has nine key components -- malting, milling, mashing, brewing, cooling, fermentation, racking, and finishing.
Malting is the process of getting the barley ready for brewing. Each step unlocks the starches hidden in the barley.
The result is a finished malt. Pale malts dry at a low temperature. You kiln mild ale malts to a slightly higher temperature, which produces a deeper color in the final beer. The highest temperatures produce flavorful and aromatic malts.
Milling is the cracking of the grain the brewer chooses for the particular batch of beer. It allows the grain to absorb the water it will eventually be mixed with (so the water can extract sugars from the malt).
Mashing converts the starches, released during the malting stage, to sugars to be fermented. You then drop the milled grain into warm water in a large cooking vessel called the mash tun. Here the grain and water mix to create a cereal mash. Then strain this sugar-rich water through the bottom of the mash – now called wort.
Brewing is the process in which the wort goes to the brew kettle -- where it comes to a boil. The boiling stage of brewing involves technical and chemical reactions. Brewers add certain types of hops at different times for either bitterness or aroma.
Cooling happens after transferring the wort quickly from the brew kettle through a device to filter out the hops, and then onto a heat exchanger for cooling. The heat exchanger is tubing inside a tub of cold water. Quickly cool the wort to a point where you can safely add yeast, which doesn't grow in high heat.
Fermentation occurs when the cooled wort goes to the fermentation tank after passing through the heat exchanger. The brewer now selects a type of yeast and adds it to the fermentation tank. Here's where the yeast ferments the wort sugars into alcohol.
Racking. During this phase, the brewer moves, or racks, the beer into the conditioning tank. The brewer then waits for the beer to complete its aging process.
Finishing is the last step — filtration, and carbonation. Next the beer goes to a holding tank where it stays until brewers bottle it.
SOURCE: Seattle-based Pike's Pub & Brewery