PROC Shewhart U Chart Controling VAXIS When there are excursions greater than specified axes limits

Dlee0416 — Wed, 09 Jan 2019 15:12:08 GMT

I'm creating U charts with Proc Shewhart. The desired vaxis heights for each defect bucket are specified but occasionally we have excursions that are greater than the specified vertical axis height. In these instances the vaxis option is overridden. This causes the chart to expand the vertical axis and makes interpreting the bulk of the data challenging. Is there a way to strictly enforce the desired vaxis setting in the face of excursions? I'll attach a snapshot of one example.

Thanks for any help on this.

%let defects='List of defects'

%let orderlabel='List of descriptions'

%let maxaxis='List of max vertical axes'

More SAS code and preprocessing

proc shewhart data=defects_per_grp1 gout=shew;
     by defect_category;
     uchart defects*seq(year month)%if %upcase(&b)=Y %then =&product.b;
    /npanelpos=200 subgroupn=ngrp nolegend html=alt vaxis=0 to &this_max_axis by &this_incr vref=&median lvref=3 cvref=green;
     label year="Year" month='Month' %if %upcase(&b)=Y %then &product.b="Product";;
  run;

Re: ROC Shewhart U Chart Controling VAXIS When there are excursions greater than specified axes limi

PaigeMiller — Wed, 09 Jan 2019 15:12:06 GMT

See the CLIPFACTOR= option in PROC SHEWHART.

Re: ROC Shewhart U Chart Controling VAXIS When there are excursions greater than specified axes limi

Dlee0416 — Wed, 09 Jan 2019 15:44:12 GMT

Thanks Paige! This looks promising but the documentation is somewhat slim on exactly what's being clipped. I searched and found one of your posts from a few years ago asking the same question.

Dave

topic Re: ROC Shewhart U Chart Controling VAXIS When there are excursions greater than specified axes limi in Statistical Procedures

PROC Shewhart U Chart Controling VAXIS When there are excursions greater than specified axes limits

Re: ROC Shewhart U Chart Controling VAXIS When there are excursions greater than specified axes limi

Re: ROC Shewhart U Chart Controling VAXIS When there are excursions greater than specified axes limi