V
vavrochj
Hi everybody,
my question refers to a machine capability study methodology (also known as short-term capability study with Cmk index). I was looking for the answer in all the threads but without success. I have been working in automotive industry for a quite long time but this is still not clear for me.
Quality standards and also our customers ask us to carry out the machine capability studies prior to the start of serial production. But the problem is in 2 different approaches/understandings of the machine capability study:
1) Some procedures speak about machine capability study in case of purchasing a new machine to be sure that the new machine is able to produce in the way our customers are requiring. In this case the process parameteres are recommended to be measured during the study.
2) The second approach is usually taken by the car makers. They often push us to make this study (Cmk) for each new project before we are able to present them Ppk or Cpk evaluation. In this case the product parameters have to be measured.
What is your opinion on these two approaches? Which one is the correct one? Is it the right way to do the machine capability study only for new machines and try to explain to our customers that Ppk and Cpk studies are enough for the product/process validation during development phase. Or do you see another solution?
In what way do you carry out the machine capability study in your practise?
Thank you very much for any kind of help, comments or opinions.
my question refers to a machine capability study methodology (also known as short-term capability study with Cmk index). I was looking for the answer in all the threads but without success. I have been working in automotive industry for a quite long time but this is still not clear for me.
Quality standards and also our customers ask us to carry out the machine capability studies prior to the start of serial production. But the problem is in 2 different approaches/understandings of the machine capability study:
1) Some procedures speak about machine capability study in case of purchasing a new machine to be sure that the new machine is able to produce in the way our customers are requiring. In this case the process parameteres are recommended to be measured during the study.
2) The second approach is usually taken by the car makers. They often push us to make this study (Cmk) for each new project before we are able to present them Ppk or Cpk evaluation. In this case the product parameters have to be measured.
What is your opinion on these two approaches? Which one is the correct one? Is it the right way to do the machine capability study only for new machines and try to explain to our customers that Ppk and Cpk studies are enough for the product/process validation during development phase. Or do you see another solution?
In what way do you carry out the machine capability study in your practise?
Thank you very much for any kind of help, comments or opinions.