I'm being asked by a potential customer if I'm familiar with "PCN process and notification". My company does not normally make changes to products other than to substitute components that are functionally equivalent. A different brand of resistor, or capacitor, sometimes chips, are used when the original part is not available. I don't generate a PCN for such changes. Is there any sort of a formal specification for when a PCN needs to be generated? One of the things I plan to do on this new design, is to provide the ability to use modified pinouts of otherwise similar parts. One of the parts I use has options for polarity of the control on an analog switch. They've always been bought as the low true enable version. There's also a high true enable version and one with mixed polarities. By "telling" the FPGA which version is on the board, the polarity can be configured using a pair of resistors, or possibly just one. I would make these configuration selections available in a status register, so the system can track and report the BoM options. But these would not be PCN issues. How do you decide what is and what is not PCN worthy? -- Rick C. - Get 1,000 miles of free Supercharging - Tesla referral code - https://ts.la/richard11209
PCN Process and Notification Specification
Started by ●November 23, 2022
Reply by ●November 25, 20222022-11-25
On Wednesday, November 23, 2022 at 9:50:17 PM UTC, Ricky wrote:> I'm being asked by a potential customer if I'm familiar with "PCN process and notification". My company does not normally make changes to products other than to substitute components that are functionally equivalent. A different brand of resistor, or capacitor, sometimes chips, are used when the original part is not available. I don't generate a PCN for such changes. > > Is there any sort of a formal specification for when a PCN needs to be generated? > > One of the things I plan to do on this new design, is to provide the ability to use modified pinouts of otherwise similar parts. One of the parts I use has options for polarity of the control on an analog switch. They've always been bought as the low true enable version. There's also a high true enable version and one with mixed polarities. By "telling" the FPGA which version is on the board, the polarity can be configured using a pair of resistors, or possibly just one. > > I would make these configuration selections available in a status register, so the system can track and report the BoM options. But these would not be PCN issues. > > How do you decide what is and what is not PCN worthy? > > -- > > Rick C. > > - Get 1,000 miles of free Supercharging > - Tesla referral code - https://ts.la/richard11209(wow, all these QA engineering questions on SED, lately; must be all the mood-boosting turkey l-tryptophan ;0) yes, there are MIL and EIA standards for configuration control e.g., EIA-649C. Actual examples of a PCN I dont have, but I think copying one of the major makers do is a good start. A maker who is under ISO9k would probably be issuing these. My questions would be, as a start: - Do your business needs compel you have such a system (even a simple one)? (e.g. contractual obligations, i.e. your customer is the government or is a contractor (up to some level, the government). If so, then follow the standard(s) quoted in the contract. If not, but you are seeking best quality management, then - do you have an document that defines criteria for when a any change (including BOM) is formal engineering change? - if so , then how to classify the change (e.g. minor, major, critical) & how to document it? - for given criticality, who needs to approve that change? --- E.g., if the change affects form, fit, function in anyway, we could define that higher-than-minor. It will need some review by other engineers. - analyze the impact of that change. does it translate to - notifying customers? setting a new product version? Recently, due to supply chain problems, I have seen manufacturers alter the public model ID suffix, e.g., 77XYX1234XXXA to 77XYX1234XXXP because one key processor chip had to be swapped out with another similar -but not identical- part. I presume, "enough" things had to change in their process to make this substitute part work as equally well to the original part. The typical consumer customer would not notice the letter change, (but few of us have jobs that track these things!). All this extra work is costly. Of course you have to determine if your customers really need this traceability, and then figure out the added costs.
Reply by ●December 23, 20222022-12-23
On 24/11/22 08:50, Ricky wrote:> I'm being asked by a potential customer if I'm familiar with "PCN process and notification". My company does not normally make changes to products other than to substitute components that are functionally equivalent. A different brand of resistor, or capacitor, sometimes chips, are used when the original part is not available. I don't generate a PCN for such changes. > > Is there any sort of a formal specification for when a PCN needs to be generated? > > One of the things I plan to do on this new design, is to provide the ability to use modified pinouts of otherwise similar parts. One of the parts I use has options for polarity of the control on an analog switch. They've always been bought as the low true enable version. There's also a high true enable version and one with mixed polarities. By "telling" the FPGA which version is on the board, the polarity can be configured using a pair of resistors, or possibly just one. > > I would make these configuration selections available in a status register, so the system can track and report the BoM options. But these would not be PCN issues. > > How do you decide what is and what is not PCN worthy? >Microchip sends out PCNs if you ask them. Changes of production lines, EOL etc. -- Marty
