Manufacturing equipment presents inherent dangers for operators and maintenance personnel. To reduce safety risks, plants often stop belts, rollers and other operationally critical machinery during maintenance activities. Contemporary safety technologies can substantially reduce machinery downtime and improve productivity.
Safety technologies and techniques used by some of the world’s safest companies improve both safety and productivity. That’s because safety and productivity are directly related, said Steven Ludwig, program manager, Rockwell Automation.
“Safety can improve performance, and one of the ways that happens is through technologies and standards,” said Ludwig, who led a session at the Rockwell Automation RSTechED event in San Diego on June 11.
These “best-in-class” manufacturers are exceeding their performance goals by integrating their automation systems with their safety-control system and adopting technologies that enable safe maintenance without compromising productivity. They’re also tapping into their manufacturing intelligence systems to gain insight into the root causes of equipment safety issues.
Manufacturers that haven’t built safety into their overall performance objectives risk much more than workers’ compensation losses or OSHA violations. Globalization has placed more pressure on companies to be socially responsible. For instance, Apple Inc. faced intense public scrutiny in 2012 after a New York Times article revealed employee abuses at a Foxconn plant that assembles Apple products.
“If your reputation is damaged as a company, people may stop buying your product,” Ludwig said. “So the effect on revenues can be much higher than a fine.”
In addition, more stringent safety standards outside North America shouldn’t encourage manufacturers to take short-cuts at home. Europe’s ISO 13849-1 standard requires that machine builders document the safety performance level of the machine, which includes mean time to dangerous failure. Many U.S. manufacturers only adhere to such safety standards when shipping machinery overseas. These companies risk hefty lawsuits in the U.S. if a court rules that they were negligent, Ludwig said.
“You can’t just meet local safety standards because eventually you’ll face a lawyer in a courtroom,” Ludwig said.
Safer Plants Are More Productive
Advancements in machinery safety technologies and automation help manufacturers mitigate some of these safety risks while increasing productivity. Safe-speed controls have helped manufacturers increase efficiency while maintaining a safe work environment during maintenance activities. This technology slows the moving machine part, such as a conveyor belt or roller, down to a safe level so a technician can work on the equipment without stopping it.
“In the old method, as soon as you open a safety door the line stops,” said Chris Brogli, global business development safety manager, Rockwell Automation. “They could only clean one section at a time, so they may be stopping the line 50 to 60 times in the cleaning process. Once it’s at safe speed they can open the safety door without stopping the line and clean continuously.”
One large, multinational food and beverage customer cut its machine cleaning time by 50 percent using safe-speed technology, Brogli said. Many industries that use rollers in the production process have implemented safe-direction controls to achieve similar results. For instance, the printing plants must clean the rollers that transfer print to paper periodically. In the past, these companies would stop the roller, clean a section and then bump it to the next position. Safe-direction technology allows maintenance technicians to reverse the roller direction so the part is moving away from them while they’re cleaning.
Another way manufacturers can improve efficiency during safety stoppages is through the use of zone control. Zone control allows plants to shut down one section of a multiple-zone assembly line while the rest of the line continues to operate, Brogli said.
Automation and Safety Systems Converge
Manufacturers can gain more insight into potential safety issues by integrating their safety technology with their automation control systems. In the past, most plants have kept these systems separate. But one control platform can minimize the costs associated with managing two disparate systems. It also allows companies to make full use of the data in their automation system to make more intelligent decisions around safety, Ludwig said.
Forty-seven percent of manufacturers that Aberdeen Group considers best-in-class integrated safety with their standard control systems, according to a 2010 Aberdeen Group report. These manufacturers had a 90 percent operational equipment effectiveness (OEE) rate and a 0.2 percent repeat accident rate. Meanwhile, laggard companies had a 76 percent OEE rate and 10 percent repeat accident rate.
Beyond physical machine safety, manufacturers can implement software that tracks any changes to safety control codes that may generate a fault. FactoryTalk AssetCentre software from Rockwell Automation is a tool manufacturers can use to audit controller code changes.
“You can see everything that operator has done and make sure no fault was wrongly interjected,” said Mike Pantaleano, business manager, Rockwell Automation.
While technology plays a major role in manufacturers’ ability to create a safe work environment, they can take other proactive steps to reduce hazards. This includes assessing their own safety maturity. In the coming months, Rockwell Automation will launch a tool that will help customers determine their safety maturity level, including their culture, compliance policies and procedures, and use of safety technology, Ludwig said.