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Be Rational With Machine Safety

Nov. 23, 2010
When it Comes to Industrial Safety Think Rational, Not Rationalized
By Joe Feeley, Editor in Chief

At the Safety Automation Forum, which preceded the Rockwell Automation Fair in Orlando this year, Jeff Russell of the American Beverages Division of PepsiCo Americas discussed global safety compliance via international standards.

His company is moving from EN 954-1 to EN ISO 13849-1 performance-level-based evaluation of its machine builders' designs, with emphasis on the safety aspects up front in that process.
"Our machines 'travel' and could be built for one region, but be relocated to another," he explained. "The design standards have to be the same."

[pullquote]Russell said the company had to work out internal discrepancies in standards-based assessments of machine designs. In the early stages of company-wide harmonization activities, his committee determined that all machines must be fully locked out/tagged out before clearing minor jams. "We can't do that," Russell recalled saying. "The ANSI spec doesn't require it, and many of the legacy machines aren't built for that. A full lock out/tag out will result in a 10-minute restart to clear a 30-second jam. What do you think the likelihood is that operators will comply with that?"

After a few iterations, they recognized reality and accepted the ANSI approach that didn't dictate a full shutdown for legacy machines with infrequent faults. "But, if a machine has a lot of faults that require manual intervention to clear the system, then we'll bring that machine up to Cat 4 safety."

Another reality is getting OEMs to comply with risk-assessment assurances. "We said machine builders had to provide risk assessment," recalled Russell. "We got zero response to that. The builders wanted to simply say that they deemed a particular level to be sufficient, and that they did that." So, PepsiCo asked the machine builder to provide evidence that it had actually done a risk assessment, what standard it used and a statement of its thoroughness, Russell said. "They had to tell us how it affected the HMI or the operator manual, for example." Russell recognized this, too, is a work in progress with his OEMs.

Greg Andersen, author of Safety 24/7 and CEO of Results in Learning, spoke at the Safety Forum about company safety culture and the primary reasons that explain a worker's unwanted, but often natural tolerance of risk. Andersen identified one reason as the often-too-typical case in which the supervisor tells an employee that a critical job must get done without fail. At shift's end he returns to find the job complete and praises the worker for a job well done. "The supervisor doesn't know that to get the job done, the worker didn't use correct PPE, didn't follow a number of policies and procedures, maybe didn't consider safety at all," he said. "The supervisor has rewarded the employee for safety behavior his company didn't want."

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