WindAddict2
Electrical
- May 11, 2017
- 2
This is a question for my own education, I am the account manager, but have an EE, and no formal Quality Training ( well I have done some over my career)
I have a client what we sell a mature electronic product to ( 3rd Generation, and 3rd V of that) - we produce >300K per year, they buy ~7K per year. We have published MTBF per SN29500 of ~3000FIT ( 40C) and observed FIT of ~200 looking at the population at large, including previous Versions that included elements that have been improved today. The customer population at large is 30K we estimate they collectively see about 100 failures per year - i.e. so as I calculate it their rate is in line without broader experience - I suspect their product is in service nearly 100% but running on average 10-30%. The ambient temp is affected by the loading of the system, not just is it on or off. Also - based on warranty analysis less than 10% of failures are product failures - this gets used in a way that any disturbance (lighting, controls mis-opp) or poor application (there are external design factors that affect our component), as well as overall system maintenance ( cooling in particular) results in higher failures. i.e. well engineered and applied systems are 100x or more reliable than
Our component is a sub-assembly with est 100 electronic sub components ( Res, Caps, ICs, Magnetics - small signal transformers - etc) --
They have hired a new Reliability Engineer that is insisting that we should be able to "test" our reliability for the assembly, and provide info on the failure modes. I contend that we can not construct such a test since the MTBF is too high, that the Calculation via SN29500 and our field data is the best info. Furthermore, since this is a general purpose item, failures specific to their application need to be analyzed by looking at their field failures.
Also - the devices are one of the main sources if heat; so raising the ambient temp is not a good acceleration factor because it may cause some materials and elements to age in a way that is not observed in the reality.
Our quality team is very good and very serious, and I do not want to bring them a customer and "problem" that is obviously not valid. Also - I do not believe the customer's RE has read our publications, AP notes and other info relating to this matter, he seems to keep falling back to what I will call "textbook" methodology and wants us to spoonfeed him answers.
Am I way off base in my analysis - is it viable to construct an accelerated test that can yield meaningful info with a sample size of about 1/1000 of the MBTF figures. The assembly cost >$500 - so a 1000 pc test is not realistic.
I have a client what we sell a mature electronic product to ( 3rd Generation, and 3rd V of that) - we produce >300K per year, they buy ~7K per year. We have published MTBF per SN29500 of ~3000FIT ( 40C) and observed FIT of ~200 looking at the population at large, including previous Versions that included elements that have been improved today. The customer population at large is 30K we estimate they collectively see about 100 failures per year - i.e. so as I calculate it their rate is in line without broader experience - I suspect their product is in service nearly 100% but running on average 10-30%. The ambient temp is affected by the loading of the system, not just is it on or off. Also - based on warranty analysis less than 10% of failures are product failures - this gets used in a way that any disturbance (lighting, controls mis-opp) or poor application (there are external design factors that affect our component), as well as overall system maintenance ( cooling in particular) results in higher failures. i.e. well engineered and applied systems are 100x or more reliable than
Our component is a sub-assembly with est 100 electronic sub components ( Res, Caps, ICs, Magnetics - small signal transformers - etc) --
They have hired a new Reliability Engineer that is insisting that we should be able to "test" our reliability for the assembly, and provide info on the failure modes. I contend that we can not construct such a test since the MTBF is too high, that the Calculation via SN29500 and our field data is the best info. Furthermore, since this is a general purpose item, failures specific to their application need to be analyzed by looking at their field failures.
Also - the devices are one of the main sources if heat; so raising the ambient temp is not a good acceleration factor because it may cause some materials and elements to age in a way that is not observed in the reality.
Our quality team is very good and very serious, and I do not want to bring them a customer and "problem" that is obviously not valid. Also - I do not believe the customer's RE has read our publications, AP notes and other info relating to this matter, he seems to keep falling back to what I will call "textbook" methodology and wants us to spoonfeed him answers.
Am I way off base in my analysis - is it viable to construct an accelerated test that can yield meaningful info with a sample size of about 1/1000 of the MBTF figures. The assembly cost >$500 - so a 1000 pc test is not realistic.