- THE MAGAZINE
- FOOD MASTER
Food Engineering's first "Essential Guide To Manufacturing Software," published two years ago (May, '99), was an effort to help food manufacturers "navigate the maze" of solutions offered by software vendors and make the right investment decisions to meet their particular needs.
It's time for an update. The technologies continue to explode faster than they can be applied. New systems are continually introduced. Systems incorporate ever-greater functionalities and capabilities, blurring layers of control and definitions. Mergers, acquisitions, new players and dropouts have altered the vendor lineup. The expanding lexicon of acronyms and abbreviations continues to confuse. And the Internet is changing everything, raising premature expectations of "e-commerce" yet opening real opportunities for supplier/customer collaboration.
Defacto standardsSoftware systems seem more open to each other today than ever before as vendors almost invariably adopt Microsoft standards such as the Windows NT, '95 or 2000 operating systems; Microsoft Distributed interNet Applications for Manufacturing (DNA-M) which include object linking and embedding for process control (OPC), ActiveX, Visual Basic for Applications (VBA), Open Database for Connectivity (ODBC) and SQL server; Extensible Markup Language (XML) to better integrate manufacturing with information systems; and the recently-published ISA-95 (formerly S95) standard for integrating control systems with enterprise systems.
Microsoft standards have been implemented for process control "because they're pervasive in the enterprise," observes John Blanchard, principal analyst at the ARC Advisory Group (Dedham, MA). "The enterprise wants business data in the form it's been using at the business level -- that's what pushed MS standards into the control system."
But -- how open is open?According to Food Engineering's 2001 Best Practices Survey (Feb., '01), there has been little improvement in integrating equipment on the plant floor itself or in integrating the plant floor with upper-level business systems over the past two years. Forty-four percent of survey respondents report "scattered islands of control" and only nine percent report "top to bottom integration," both little changed from a year earlier. There seem to be several reasons why integration is lagging on the plant floor:
- Most food manufacturers have large installed bases of manufacturing equipment incorporating OEM controls or controls from varying vendors, making it difficult and costly to integrate these legacy systems. This was confirmed by the Best Practices survey: When asked what types of process controls are installed in their plants, 53 percent of respondents included "individual microprocessor-based machine controls" among their answers. It seems that integration on the plant floor will occur only gradually as equipment is replaced over time.
- Vendors have only gradually adopted standards which open their systems to each other. "For a supplier, the more open your system, the less captive your market and the less reason your installed base has to stay with you," observes Blanchard. With growing vendor adoption of standards "that's changing, but not as rapidly as it could."
- The continuing need to shift from manufacturing to inventory to manufacturing to demand -- from "push" to "pull" -- impacts on the plant floor. In a typical food plant, Blanchard observes, receiving and storage pull from suppliers, and initial processing pulls from receiving and storage. But processing pushes into finishing (further processing), finishing pushes into packaging, and packaging pushes into warehousing. This creates in-plant inventory. "You have more in-process material, more work-in-progress, because you're not making to order," he points out. "You have significant inventory sitting in the plant itself, not just in the warehouse, because you don't have a 'pull' situation. If you're pushing, it's an 'island of automation.'"
- New technologies and standards are needed on the plant floor. "Why must finishing push into packaging?" Blanchard continues. "Why can't the packaging line know what it needs, or why can't the finishing area let packaging know what's coming?" Packaging-line changeover today is typically a mechanical operation, but motion-control technology incorporating for example "smart servos" will shift changeover from a mechanical operation to a software function, allowing closer integration between processing and packaging. (As reported earlier by FE, the Open Modular Architecture Controls [OMAC] Users Group, composed of supplier and food-manufacturer representatives, is working toward defining guidelines for motion-control architectures and programming languages.)
- Corporations are prioritizing the integration of IT systems with each other rather than with plant systems. According to the Bureau of Economic Analysis, only 5 percent of IT investment is spent on manufacturing execution and asset management. In the food industry, recent giant mergers and acquisitions mean that companies must quickly consolidate their financial, accounting, inventory and distribution systems. These will likely take priority over manufacturing integrations in the short term.
Growing functionalitiesAlthough some islands are slow to integrate, "improved automation and process control" ranked a close third behind "improved training" and "improved equipment" as a reason for the dramatically improved manufacturing results reported by respondents to FE's Best Practices survey.
This may be partly due to the ever-increasing functionalites offered by today's plant-floor process control systems. As reported earlier by FE (March, '01), supervisory control and data acquisition (SCADA) has become more difficult to define as these systems add more production-management and manufacturing-execution functions, blurring the distinction between SCADA and MES (Manufacturing Execution Systems). A typical SCADA system integrates PLCs with a PC. Today, that integration increasingly includes HMI (human/machine interface), a PC with graphic process and machine-status displays, alarms., messages, diagnostics, database access, reporting tools and automated process execution, allowing operator feedback.
Major vendors now call these systems HMI/SCADA, and their latest releases incorporate the Microsoft DNA-M standards cited earlier plus Web portals for integrating via Internet across the enterprise using XML, and accessible via Web browser from "thin clients" anywhere in the enterprise. As reported by Kevin Prouty, reearch director for manufacturing strategies at AMR Research (Boston), "the Web is transforming automation systems without engineers knowing it. When engineers weren't looking, companies like Rockwell Automation and Schneider Electric slipped Web servers into their PLCs." As reported last month by FE, the latest HMI/SCADA systems from Wonderware, Intellution, National Instruments, Citect and Camstar also incorporate Web portals accessible by thin clients via Web browser. Systems integrators who can mix-and-match software to customize control and information systems to the user's specific needs are becoming more important than ever.
Integration via Internet will enable close collaboration between manufacturers and customers to eventually achieve that elusive goal of Efficient Consumer Response (ECR). But trusting relationships and integration with well-developed customer standards must evolve before food manufacturers can truly collaborate with retail and food-service across the supply chain, said William R. Friend, retired vice-president of the J.R. Simplot Food Group, at Food Engineering's Food Automation 2001 conference last February in Fort Lauderdale, Fla. In the absence of trust, however, collaborative forecasting and production-planning will be driven by:
- Government regulations relating to food safety and trace/recall procedures;
- Giant retailer consolidations, forcing manufacturers to reduce production and distribution costs and shift manufacturing strategy from "push" to "pull;"
- Demands to improve order-fulfillment rates and shelf-life requirements;
- "Channel masters," the retail and foodservice giants such as Wal-Mart, McDonald's, Kroger and Sysco, who will dictate the integration standards.
Software surveyIn our software survey, we asked vendors to list only systems designed for process manufacturing (not discrete) or hybrid systems which offer both process and discrete capabilities. We also asked them to list system type or the functionalities provided by each system.
Sitebar:Mrs. Smith's Bakeries automated recipe-management, batch control, dough-handling and pie-filling operations as part of a major expansion and renovation project which enlarged its frozen pie plant at Stillwell, Okla, by more than 50 percent into a nine-acre facility during an 18-month project completed in August, 1999. Other than hand-added ingredients and shortening, no human intervention is needed between dough mixing and delivery to the plant's six pie lines. Now the nation's largest pie plant, the facility produces 48,000 lbs. of dough per hour and 530 pies and cobblers per minute!
Automation 'easy as pie' at Mrs. Smith's
Every day, the plant requires five truckloads of sugar, 13 truckloads of flour, 300 pallets of fruit and 178 pallets of margarine, so scheduling batches and tracking ingredient use is critical. A multilayered control system engineered by EMTROL, Inc. automates batching, handling and delivery of dough to the pie lines, as well as filling operations. EMTROL supplied the dough-handling system, its control software, validated the system through computer simulations before installation, and assisted with systems integration.
The system integrates an EMTROL Automated Trough System (ATS), EMTROL PIMS (Production Information and Management System) software, a Microsoft SQL server database, 20 Allen-Bradley PLCs, five cell controllers and 11 operator-interface stations running Rockwell RSView32 software, 13 Allen-Bradley PanelView operator terminals and 13 barcode readers.
The ATS is a laser-guided, PLC-controlled closed-loop automated storage and retrieval system situated between the four dough mixers and elevated conveyors which carry the dough to dumper stations at the head of each pie line. A stacker crane moves horizontally between two rows of storage racks capable of holding more than 300 loaded and empty custom-designed stainless-steel troughs on six levels. A transfer vehicle with two-trough capacity delivers filled dough troughs to a shuttle vehicle carried on the stacker crane. Together, crane and shuttle deliver troughs to designated rack positions and record each trough's "address" with a barcode scanner. The trough remains at its designated location for several hours as part of a retarding process which improves the flaky texture of the dough. When dough in a given trough is ready, the trough is retrieved and moved to an elevated conveyor supplying one of the pie lines.
PIMS orchestrates the entire dough-delivery and pie-filling process including dynamic scheduling to ensure a constant supply of dough and filling to the pie lines; rack-positioning troughs for maximum throughput with minimal handling; and moving individual troughs throughout the system. The ATS communicates with cell controllers via the plant's Ethernet, and executes one mission every minute.
Integrated batch control
To start the process, the mixer cell controller queries the database to determine if a batch is scheduled. If so, batch information is downloaded from the database, and converted into recipe and ingredient instructions by RSView32 and transmitted to the Shick ingredient-delivery system and mixer controllers.
The Shick system feeds ingredients into four high-volume San Cassiano mixers. When a mix is complete, the mixer signals the ATS to deliver a trough. The mixer dumps a batch of dough weighing up to 1,000 lbs. into a trough; the trough is scanned for identity; moved through two stations where the dough is compressed and the trough is lidded, and the trough is delivered to the rack system as a new empty is dispatched to a mixer.
When a trough is retrieved from the rack system, the ATS delivers it to an EMTROL dumper, where it is scanned to assure identity and dumped onto an elevated belt conveyor supplying one of the pie-shell molding machines. After dumping, the trough is weighed to confirm that it's empty, then either returned to staging or routed at pre-set time intervals to washing and drying stations. Meanwhile, PIMS also controls the fruit and custard-cooking and filling processes. Along the way, RSView32 HMI stations allow operators to monitor the process and make changes when necessary.
EMTROL, Inc., 3050 Hempland Road, Lancaster, PA 17601. Phone: (717) 397-2531; Fax: (717) 393-7230; Website: www.emtrol.com
Rockwell Automation, 1201 South Second St.,Milwaukee, WI 53201. Phone: (414) 382-2000; Fax: (414) 382-4444; Website: www.rockwellautomation.com