A biotechnology customer of GE Fanuc wanted to replace its analog strip chart recorders with digital versions. But engineers at the company first decided to see if the historian in their automation system was up to the task. “The historian was able to do the job, and it was a low-intensity effort to make it work,” observes Jack Wilkins, senior manager for Proficy Software at GE Fanuc Automation, in Charlottesville, Va. “We took the industrial-strength historian and used it as a strip chart recorder and sent the data to their portal.”
Now, plant operators can go to the portal and see the strip chart data. “They can look for a temperature over time, and if it exceeds a certain level, they can bring in maintenance,” says Wilkins. The cost of using the historian as a strip chart recorder was 60 percent less than the cost of acquiring electronic strip chart recorders. Beyond the ability to monitor plant deviations, the biotech customer also uses the data from the historian to provide batch information for regulatory compliance. “They’re e-mailing the regulatory information automatically, and the foundation of it all is the historian,” Wilkins says.
The use of historians for varied purposes is growing in plant operations. Uses include process improvements, efficiency gains, quality assurance and regulatory compliance, and even as a conduit to send consumption and production information to the enterprise resource planning (ERP) system. “We’ve seen proven successes using historians and manufacturing databases to reduce overall product defects, increase quality and consistency of both products and manufacturing processes,” says Rob McGreevy, business manager for MES (or manufacturing execution system) applications at Rockwell Automation Inc., in Milwaukee. “We’ve also seen this technology deliver reduced downtime and broad gains in overall efficiency.”
Match the golden batch
Plant operators are using historian technology to improve plant efficiency. This can include everything from measuring current batches against a “golden batch” for quality, to identifying and relieving plant bottlenecks. The golden batch becomes the target for efficiency. Any plant activity that deviates from the mapped golden batch can be identified for correction.
The rule of thumb in process improvement is that you can’t improve what you can’t measure. The historian gives plant operators the measurements they need for process improvements. “When you do an analysis of the justification for a historian, one area of benefit is quality, another is yield, another is saving time, being able to compare lab data with process data,” says Eddie Whitfield, director of solution marketing in the manufacturing group for Walldorf, Germany-based SAP AG.
As well a improving the production process and using plant data to stabilize and improve batch quality, the data can also be analyzed for time savings. “One of the things the historian is regularly used to do is reduce cycle time by measuring the plant results and optimizing the plant equipment and plant operations,” says Dave Henry, director of hardware interfacing products at Brooks Software, a division of Brooks Automation Inc., Chelmsford, Mass. “Most users have reported a 25 percent to 40 percent cycle time reduction.”
The comparison of specific batches against the ideal batch can help companies create a data template to help control variations, bringing batches more in line with the quality ideal. “Being able to plot or trend detailed data from historians against batch specific events—such as transitions between phases or stages—allows for detailed analysis,” says Rockwell’s McGreevy. “In an overlay mode, some plant operators will plot the golden or ideal batch against in-process batches to better control the quality and consistency of the different batch runs.”
Time-based data
Because historian data can be measured on the run over time, plant operators have started using it to track temperatures and identify exceptions in the plant operations. The historian can be used as a monitor that can identify when temperatures or other measurements exceed historical norms, and the data can also be used to investigate and analyze problems in plant operations.
The data in the historian give operators the raw materials that can be used to diagnose problems or identify opportunities for improvement. “The historian has a huge diagnostic function. If you store all of the events, all of the time, you can go back and learn something,” says Matt Miller, manager of OEM services at OSIsoft Inc., San Leandro, Calif. “You can’t match the historian for collecting data, unless you’re standing with a clipboard and writing real fast.”
The historian can also be used to backtrack through the data history to find out what caused a bottleneck in the plant. “With the repository of data in the historian, it only takes a small amount of effort to see what caused a bottleneck,” says Randy Harris, product manager for Brooks Software. “You can see what led up to the bottleneck. All you have to do is capture data in the repository any time a field changes.”
Because the historian receives real-time data, it knows what materials have actually been consumed and what batches are complete. The historian can send this data up to the business process center to let the ERP system know what inventory has been depleted and what finished goods can now be invoiced.
This historian has become a primary link between plant floor data and the ERP system. “The use of historian technology is part of a dramatic surge of interest in integrating manufacturing into the broad supply network. They’ve talked about it for years, and now they’re doing it,” says Rick Bullotta, chief technology officer and co-founder at Lighthammer Software Development Corp., an Exton, Pa.-based provider of enterprise manufacturing intelligence software that was recently acquired by SAP.
That integration can bring benefits such as automating the flow of data to the ERP so it can package the data for reporting or supply chain functions. “You can use the historian to continuously improve cost minimization. You can repurpose to automate your environmental reporting,” says Bullotta.
The historian can also provide the data backbone for automating a flow of order status information to customers. “The historian gives the plant real visibility. You can automate it so if anything happens that might make the order late, it will notify the customer by e-mail and respond back to determine action,” says Brooks’ Harris. “The activity manager extends the event to execution capability.”
Regulatory compliance
Regulatory compliance has driven many plants to adopt historian technology. The pharmaceutical industry, as well as food and life sciences, have to create genealogical records of ingredients and plant processes. Historian technology allows the plant to gather and store batch records and also to automatically gather and submit compliance data to regulatory bodies. “The historian gives you traceability. It tells you how the batch was made and who the operator was, and what the recipe was,” says SAP’s Whitfield. “That data is stored and put into transactional data that can be pushed up to the ERP system.” He notes that the data fills the compliance need for pharmaceutical and chemical companies that supply the pharmaceutical industry.
Many plants have adopted historians for the sole purpose of satisfying regulatory demands. “Some regulations now call for plants to provide the genealogy of the process in a day or two, and that accelerates the demand on electronic systems,” says Jim Frider, product manager for plant intelligence products at Wonderware, a Lake Forest, Calif.-based division of Invensys. “Doing it by paper would take a long time.
Historians and databases are becoming widely used in plant operations. This technology—particularly the historian—has become the measurement tool for process improvement, quality assurance, deviation warnings, regulatory compliance, and the data bridge between plant operations and business processes. “Plant operators know they’re going to use the historian for multiple purposes, more than just storing data,” explains SAP’s Whitfield. “They’re going to use it for statistical process control analysis so they can recognize when things are drifting.”
In most cases, the historian is being used for one specific task, but once it’s in place, plant operators start to extend its use to other applications. “In pharmaceutical manufacturing and at plants with Environmental Protection Agency emissions controls, adoption is being driven by regulations. At power plants, it’s being driven by process improvement,” says OSIsoft’s Miller. But once the historian is in place, streaming data, that data inevitably gets used to help plant operations in other areas.
See sidebar to this article: Historians vs Databases
