- Perform a hazard or risk assessment. Identify hazards and estimate the associated risk.
- Determine the functional safety system requirements. Evaluate safeguarding options based on industry-acceptable solutions and select mitigation techniques. "This includes more than hand protection on a press," Ludwig explained. "It can include recognition of a strain hazard, where someone has to lift a 50-lb. bag into a bin four feet off the ground. Considering an increasingly aging workforce or younger workers who tend to take more risks, do you design in an automated lift or find another design with a lower lift requirement?"
- Design and verify the system. Design system architecture, document safety circuit design, procure materials. "This is where we have a lot of our tools," Ludwig detailed. "Rockwell Automation Safety Automation Builder helps with design of safety systems, including layout, connectivity, safety level analysis, product selection and BOM. SISTEMA (Safety Integrity Software Tool for the Evaluation of Machine Applications) is a globally accepted tool for safety calculations. It provides evaluation of safety-related control components based upon designated architectures. But it's difficult to put your numbers into the format that the calculator requires. So you can do that individually, but Safety Automation Builder simplifies it very nicely. It creates the BOM for a safety function, say, an E-stop, that requires an input device, a logic device to make the decision and an output device to respond to that decision, and then provides the calculation that flows pretty seamlessly into SISTEMA in the right format."
In addition, the company's Safety Functions tools provide complete, documented solutions to common safety applications.
Ludwig says with Safety Automation Builder you can scan the drawing of the machine showing all the access points and indicate the safety level you want according to IEC 13849.
- Install and validate the system. Verify systems are operating within defined parameters and applicable standards have been satisfied.
- Maintain and improve the system. Verify that system requirements operate within specified parameters for production and safety preventative maintenance and system upgrades.
The safety life cycle process provides the structure and tools to develop integrated safety systems that not only protect assets and employees, but also enhance machine and process up time and productivity. In the Rockwell Automation view, when safety and productivity are mutually inclusive, the attitude of employees and management begins to understand that safety should be a core company value beyond compliance to standards and regulations. This can be a key element in why and how companies become the top performers seen in the studies.
Ludwig went on to say that one of the Aberdeen studies told Rockwell Automation that end users have great need for outside resources to help with safety assessments. "Unless you're building machines in-house—as some manufacturers do—it's less expensive to hire that skill when you need it instead of trying to support it on a permanent basis in-house and not fully use it. And it can be good to get an expert set of eyes that aren't as familiar with the process as the manufacturer."