While getting ready for an important meeting, systems engineer Paul Rogers got a call from the line producing the laminated asphalt shingles that Dallas-based ElkCorp makes. The continuous web of shingle material had broken somewhere in the finished product looper, a device that snakes the web around a series of rollers to create a buffer between the cooling and cutting stations. Because downtime costs the company thousands of dollars an hour, Rogers would have to drop everything and even miss his meeting to find the cause, while the line workers rethreaded the web.

As an increasingly larger number of his counterparts at other manufacturing facilities can do now, thanks to advances in software, Rogers logged immediately onto the plant’s computer network to gain access to the company’s manufacturing execution system. Using IndustrialSQL Server from Wonderware, of Lake Forrest, Calif., he looked at the historical trends for tension. He noticed that the electrical-current load on one of the motors had been climbing steadily until the web broke. He relayed the information to the mechanics, who discovered and replaced a worn bearing.

“Within five minutes, we were able to look at our entire line, identify the problem, and go right to it to fix it,” says Rogers. And, he made his meeting, which would have been impossible in the past. Diagnosing the problem could have taken hours to days because the line is quite long, approximately a football field and a half. While engineers and mechanics pored over the line, the operators would relace the looper and run the line until the web broke again.

The key for unlocking this and other gains in operating efficiency has been advanced data-handling technology. “The trend over the last four years has been the convergence of older manufacturing technology and new information technology (IT) that has been used on the administrative-side computer systems,” observes Rogers. “Management brought me [from the IT department.] to the engineering department so engineering could take advantage of technology used on the administrative side of networks.”

Not only has the ubiquitous transmission control protocol/Internet protocol, or TCP/IP, migrated to the plant floor, but other de facto standard tools also have worked their way into manufacturing software. Microsoft’s structured query language (SQL), for example, is the key technology around which Wonderware organized its real-time database. ElkCorp uses IndustrialSQL Server to collect about 6,500 pieces of information from the line every few seconds and store them in the database for two years.

Maximizing uptime

Software in the Wonderware suite then can use the data either immediately or later. Some, such as InTouch, retrieve and analyze pertinent information in real time to display current operating information or to trigger alarms. Other software helps engineers to analyze historical data not only for troubleshooting broken webs and other problems, but also for optimizing the process. “When we have a particularly good or poor run, we can check the tensions, the temperature, percents of the raw materials, and other parameters to recreate the success or to avoid the problem,” says Rogers.

The massive database also helps engineers to optimize production in another way. They can prepare for regular maintenance shutdowns by analyzing operating data to identify any developing problems for correction while the line is stopped. During one of these analyses, Rogers noticed that one of the catchers collecting cut product for wrapping had jammed 25 times in two weeks. Because the other catchers had jammed only once or twice during the same period, he added the catcher to the list for maintenance during the next shutdown.

These kinds of analyses also can uncover ways that redeploying resources can improve productivity. Consider the experience that an automotive supplier of clutches had with software from Rockwell Software, a unit of Milwaukee-based Rockwell Automation Inc. Assembly machine and systems builder Weldun International Ltd., of Bridgman, Mich., had integrated the software into a production line containing approximately 40 automatic stations and ten manual stations for making the clutches. Management at the supplier could analyze the contributions of each operator to the line, once the equipment had been running for a while.

An analysis revealed that some operators performed certain tasks better than others. “So by simply relocating people around the line, management increased production dramatically in a matter of a week,” says Mike Zimanski, an applications engineer at Weldun. Discovering this simple way of increasing efficiency was nearly impossible before, because no way existed for compiling the information collected manually.

Hey, this pays

Despite the dividends that manufacturing execution software ...