The human element in a safety system
Safety instrumented systems (SISs) are at the center of many manufacturing plants today. It’s one more example of how technology is utilized to improve our overall manufacturing operation, and there’s no more important area of manufacturing than safety.
Plant Engineering harps on safety each issue for a simple reason-the lack of safety is potentially the greatest financial expense in any plant, and the human cost is incalculable. The use of technology to preserve and enforce safety in manufacturing always pays dividends. Safety is not a cost center; it is a profit center and should be treated as such.
As we mention in a story in this issue, a SIS “is composed of sensors, logic solvers, and final control elements for the purpose of taking the process to a safe state, when predetermined conditions are exceeded.” It’s a great advance in plant system safety, and it’s something more plants need to evaluate for their safety portfolio.
So what did we do before SIS? Well, if you look at the definition, we already had a version of SIS on the plant floor–one complete with sensors, logic solvers and final control elements. We called this system a “worker”. However advanced and sophisticated today’s SIS systems might be, we shouldn’t overlook the importance of the original SIS. The plant floor worker remains a vital part of any SIS. He needs to be every bit as integrated into safety as the technology.
As technology takes further control over the plant floor, there still must be the element of human safety control. We must create and expand an interdependent network with our workers. We should not be solely dependent on the sensors or controls to observe and respond to unsafe situations, because there still are plenty of safety situations that cannot be instrumented.
Every year the Occupational Health and Safety Administration (OSHA) releases its top 10 recordable workplace injuries. And every year the top OSHA recordable is fall protection. And even though it’s the same issue every year, the issue of fall protection never stops being the top safety issue. All the attention paid to workplace injuries in general and this issue in particular hasn’t managed to change the realities of slips, trips and falls in the workplace.
Fall protection also isn’t that easy to instrument. We can insist on security belts when we climb or operate machinery, watch for wet spots on the plant floor, and be diligent about scrap that escapes the work cell, but it’s not one of those areas we actually can monitor in the same way we do heat or vibration. We need that original sensor and logic solver-the plant worker-to be the solution.
There is one more reason to keep the worker as the core of any safety system. People care about the safety of their fellow workers, for altruistic and selfish reasons. We genuinely value our co-workers, and when they are hurt on the job, it also means more work for everyone else. Empathy is the one area of a safety system that cannot be instrumented.
If we begin with people at the core of a safety system, then the technology and the strategy will follow in line. Safety systems that begin with the technology at the core may be perfectly effective but will only be able to monitor, measure, and control the digital parameters of safety. Perhaps we will get to the day when a sensor finds a wet spot on the floor and a robot scurries out to clean it up, but we’re not there yet.
Safety is the one area of the workplace where employers have to show they care about their team. Safety is the most important workplace benefit-more than salaries or health care or 401ks. Without safety, none of those other benefits have value. A safe work-place, and the extension of safety from work to home, is the only way to ensure we have the ability to enjoy the money we earn and the money we save.
Because it is a system of sensors and logic, a SIS is always vigilant. The human safety system has to be vigilant as well.
Bob Vavra, content manager, Plant Engineering, CFE Media, firstname.lastname@example.org.