Charles, et al, You question is rather simplistic, in my opinion.
From my more than 25 years doing safety & regulatory consulting with dozens and dozens of companies both large and small, I find that the experience of the design team is the key to meeting the requirements early on. First timers (no prior experience having an outside lab test any of their work for compliance) has a pretty low pass rate; no matter how much advice is given during the design phase. Design teams quickly gain experience ramp up & meet compliance requirements on the next project or two providing the design is similar to their earlier experience. This level of competence can be confounded (made worse) if there are substantial changes in the design team between projects. Newbies always think they understand the needs and design accordingly; unless an experienced team manager can ferret out the issue before testing and get them to change. Additional features (especially radios) complicate the issue, even for experienced design teams. To specifically answer your question, first designs from an inexperienced design team generally will need another pass (or more) thru the lab to qualify. Experienced teams will have a high 1st time pass rate in most cases. To relate one scenario, a complex electronic research instrument was developed by a 3 man team of PhD physicists who struggled when going thru the EMC lab; they had no prior product certification experience. I had offered to go to the lab with them but they thought they could handle it themselves. They had no concept of the needs to provide the proper isolation between major pieces (e.g. cables routinely pierced the chassis and made connexion well within the equipment). After the 2nd failure the lab manager, a long-time colleague, talked to me and said that they weren’t listening to his comments about needed changes to fix it. Upon talking to them, they had dismissed him as just a technician (ignoring his EE training and EMC lab experience) and they believed that they knew better (but not good enough, as evidenced by the continuing failure). So we had a ‘managerial discussion’ and I went to the EMC lab with them from then on. The baling wire fixes tried at the lab showed improvement when applied and led to installing proper connectors at the chassis interfaces along with some other changes; it finally passed. Others probably have more interesting cases to relate, too. Does that fit with your experience? :>) br, Pete Peter E Perkins, PE Principal Product Safety & Regulatory Affairs Consultant PO Box 1067 Albany, ORe 97321-0413 503/452-1201 IEEE Life Fellow IEEE PSES 2020 Distinguished Lecturer <http://www.researchgate.net/Peter%20Perkins> www.researchgate.net search my name <mailto:p.perk...@ieee.org> p.perk...@ieee.org Entropy ain’t what it used to be From: Grasso, Charles [Outlook] <charles.gra...@dish.com> Sent: Monday, May 24, 2021 7:47 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] What percentage of products pass first time? Hello EMC gurus! Calling all labs - In your experience how many products pass the Unintentional Emissions test first time? - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. 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