V
vasilist
First of all i want to give a lot of thanks to : Marc, Rick Goodson and Dave Strouse for their help in my previous thread.
Let's get to work now :
one of our suppliers in chicken propably doesn't cut inside our specification limits. So i made 18 control charts measuring the weight of chicken parts (1 control chart was made in his facilities, the rest 17 in stores during a week).
Finally i saw in control charts what's happening. Not propably but surely now i know he doesn't follow our specifications. 10 control charts out of 18 were in non-conformance ( i hope i use the right words). Playing with the table of results i found the Cpk for every chart and put it in descending order.
The usual was to expect that the control charts (with conformance) with the higher Cpk would appear first. But in the 7th position there was a control chart which had non-conformance and its Cpk was 0.2987. The next two control charts were in conformance and the next 9 were out of specs. How can that be?
This is the table :
Sample Cpk Conformance
agg18 0,5855 ok
agg5 0,4608 ok
agg13 0,4304 ok
agg7 0,3910 ok
agg14 0,3587 ok
agg4 0,3505 ok
agg2 0,2987 NOT OK <--------------------
agg10 0,2697 ok
agg8 0,2453 ok
agg17 0,2067 not ok
agg6 0,0997 not ok
agg12 0,0869 not ok
agg15 0,0583 not ok
agg1 -0,0222 not ok
agg11 -0,0449 not ok
agg3 -0,1188 not ok
agg16 -0,1318 not ok
agg9 -0,1922 not ok
I hope i was clear and that i used the correct words but in any case anybody wants more details i will be more than happy to give.
Thank you in advance.
Let's get to work now :
one of our suppliers in chicken propably doesn't cut inside our specification limits. So i made 18 control charts measuring the weight of chicken parts (1 control chart was made in his facilities, the rest 17 in stores during a week).
Finally i saw in control charts what's happening. Not propably but surely now i know he doesn't follow our specifications. 10 control charts out of 18 were in non-conformance ( i hope i use the right words). Playing with the table of results i found the Cpk for every chart and put it in descending order.
The usual was to expect that the control charts (with conformance) with the higher Cpk would appear first. But in the 7th position there was a control chart which had non-conformance and its Cpk was 0.2987. The next two control charts were in conformance and the next 9 were out of specs. How can that be?
This is the table :
Sample Cpk Conformance
agg18 0,5855 ok
agg5 0,4608 ok
agg13 0,4304 ok
agg7 0,3910 ok
agg14 0,3587 ok
agg4 0,3505 ok
agg2 0,2987 NOT OK <--------------------
agg10 0,2697 ok
agg8 0,2453 ok
agg17 0,2067 not ok
agg6 0,0997 not ok
agg12 0,0869 not ok
agg15 0,0583 not ok
agg1 -0,0222 not ok
agg11 -0,0449 not ok
agg3 -0,1188 not ok
agg16 -0,1318 not ok
agg9 -0,1922 not ok
I hope i was clear and that i used the correct words but in any case anybody wants more details i will be more than happy to give.
Thank you in advance.