The upper and lower specification limits
are calculated around the desired shot size of 1.
L] index for Weibull distributed processes with the lower specification limit for product acceptance determination using the close relationship between the index [C.
where [mu] and [sigma] are the process mean and the standard deviation, respectively, and L is the lower specification limit.
Let L denote the lower specification limit of an item from the Weibull distribution; then the nonconforming rate can be defined as
The case where there are both upper and lower specification limits
which are non-equidistant from [[Mu].
So, selecting a range of 1 second (1,000 msec) between the upper and lower specification limits is fair.
After defining all parameters in selective soldering that affect solder quality and defining their upper and lower specification limits, machine capability analyses can be effectively used to quantify process control.
Thus, once a machine and mold are running good parts, the operator presses the LEARN button and continues to run for another 35-50 cycles, after which Auto-Learn will set upper and lower specification limits
on 35 SPC parameters.
where USL and LSL are the upper and lower specification limits respectively, and [Sigma] is the standard deviation of the measured characteristic.
The first involves the entry of an individual pair of upper and lower specification limits (which need not be symmetrically disposed about the nominal).
You also set the upper and lower specification limits for these parameters.
The user can specify the acceptable boundaries of deviation as equal to the upper and lower specification limits (USL and LSL) -which are automatically set for each parameter by the expert software, based on statistical analysis of an initial run of good parts - or the user can select a degree of "offset" ([+ or -] 5-20%) from those standard limits.