topic Re: SPC average for sum data in QlikView

SPC average for sum data

infock12 — Sat, 16 Nov 2024 01:42:52 GMT

Hi all,

I am trying to create an SPC chart where I have to calculate a percentage with a numerator and denominator. I am unable to work out what would be the best expression to make it work. The simple basic expression is below:

sum(Numerator)/sum(Denominator) - I've created a variable with this expression called vPercentage )

Tried average line with =avg(aggr(sum([Numerator])/sum(Denominator), [Month Year])) which seems to work

Tried a few expressions to create UCL and LCL with the below but it does not work.

vAvgLine + Stdev(aggr(Avg(vPercentage), [Month Year])) *vStdDev

I've attached the files. Any help is appreciated.

Thanks

Re: SPC average for sum data

lironbaram — Thu, 12 Dec 2019 12:00:04 GMT

have a look the attachment

your problem is that your stdev part returns null because it try to calculate it for each month alone

you need to calculate it the same way you calculate the avg in a variable

Re: SPC average for sum data

infock12 — Thu, 12 Dec 2019 13:56:33 GMT

This is fantastic. Thank you very much Liron!

Re: SPC average for sum data

lironbaram — Thu, 12 Dec 2019 18:20:24 GMT

great, i am happy it helped you