6-sigma,Cp,Cpk,Pp,Pk calculation for SPC Analysis in MII

Question

Hi,
1) Are there any built in functions or calculations available in MII to get the 6-sigma,Cp,Cpk,Pp,Pk for SPC/SQC Analysis?
2) Is it possible to enable the periodic calculation of control limits?
In past if anybody implimented the above scenarios in MII, please let me know.
I'm using MII 12.1.4.
Thanks in advance.
-Suresh
Edited by: Suresh Hiremath on Feb 17, 2010 8:17 AM

Answer 1

Hey i think u need to use following code (EST_CP instead of Cp)
var Cp=document.SPCAPP.ChartObject.getStatasticsItem("EST_CP");
Alternate way as follows
First u can get all standard params like mean, standard, lsl and usl using following codes
var x= document.SPCAPP.getChartObject().getStatisticsItem("MEAN");
var sigma = document.SPCAPP.getChartObject().getStatisticsItem("STANDARDDEVIATION");
var lsl= document.SPCAPP.getChartObject().getStatisticsItem("EFFECTIVE_LSL");
var usl= document.SPCAPP.getChartObject().getStatisticsItem("EFFECTIVE_USL");
then
     if(usl=="" && lsl!="")
                                          var Cp = "NA";
          var Cpl  = Math.round(((x - lsl)/(3*sigma))*100)/100;
          var Cpu = "NA";
          var Cpk = Math.round(((x - lsl)/(3*sigma))*100)/100;
          var Cpm = "NA";
          var Cr = "NA";
          if(usl!="" && lsl=="")
          var Cp = "NA";
          var Cpl ="NA";
          var Cpu = Math.round(((usl - x)/(3*sigma))*100)/100;
          var Cpk = Math.round(((usl - x)/(3*sigma))*100)/100;
          var Cpm = "NA";
          var Cr = "NA";
          if(usl!="" && lsl !="" )
          var Cp = Math.round(((usl - lsl)/(6*sigma))*100)/100;
          var Cpl = Math.round(((x - lsl)/(3*sigma))*100)/100;
          var Cpu = Math.round(((usl - x)/(3*sigma))*100)/100;
          var Cpk = Math.min(Cpl,Cpu);
          var Cpm = Math.round(((usl - lsl)/(6*Math.sqrt((Math.pow(sigma,2) + Math.pow(x-((parseFloat(usl)+parseFloat(lsl))/2),2)))))*100)/100;
          var Cr = Math.round(((6*sigma)/(usl - lsl))*100)/100;
Regards
Som