topic Re: How to Get Limits for Capability on IR Control Chart in Discussions

How to Get Limits for Capability on IR Control Chart

TimP — Mon, 21 May 2018 22:12:34 GMT

Hello - How can I read-in spec limits when I check "capability" in the IR chart builder?

Analyze > Quality and Process > Control Chart > IR

I have successfully read-in spec limits when studying process capability (Instructions here:https://community.jmp.com/t5/JMPer-Cable/3-ways-to-load-your-specification-limits-into-Process-Capability/ba-p/34189) but it appears to need different input when the data are stacked.

Thanks in advance,

Tim

Re: How to Get Limits for Capability on IR Control Chart

tonya_mauldin — Wed, 23 May 2018 12:41:50 GMT

You were a bit unclear as to how your specification limits are stored. You mention that your data is stacked which I assume means you are using a By variable in your analysis. Below is some general IR chart code that you can use with a by variable and specification limits.

Control Chart(
	SendToByGroup( {:Label == "height"} ),
	Group Size( 1 ),
	KSigma( 3 ),
	SendToByGroup(
		{:Label == "height"},
		Chart Col(
			:Data,
			Individual Measurement,
			Moving Range
		),
				Capability(LSL(50),Target(60),USL(70));
	),
	SendToByGroup(
		{:Label == "weight"},
		Chart Col(
			:Data,
			Individual Measurement,
			Moving Range

		),
		Capability(LSL(60), Target(70), USL(80))
	),
	By( :Label )
);

Re: How to Get Limits for Capability on IR Control Chart

TimP — Thu, 24 May 2018 19:03:40 GMT

Thank you Tonya. My spec limits are stored as in their own table (picture attached).

And you are correct, I am using a By variable since data is stacked. Is there a way to use the "Get Limits" button to pull in the spec limits under this scenario? It seems with using the code I would still be manually inputting the limits.

Re: How to Get Limits for Capability on IR Control Chart

txnelson — Thu, 24 May 2018 19:17:10 GMT

If you split the data table by the "By" column(s)

Tables==>Split

into separate columns, you can then apply the spec limits independently to each of the new columns by using the

col<<set property("Spec Limits", {USL(xxx),Target(xxx),LSL(xxx)});

Re: How to Get Limits for Capability on IR Control Chart

tonya_mauldin — Thu, 24 May 2018 19:26:21 GMT

First of all, the Get Limits check box that you are referring to is for Control Limits. This check box does not have anything to do with Spec Limits and it does not allow you to use a spec limits table. You can't store your specification limits as column properties since your data is stacked. Your only option would to be to feed these values in through JSL. You could use the code I supplied earlier. Where the spec limits are hard coded in my script, you could refer to specific cells in your spec limits data table.

Re: How to Get Limits for Capability on IR Control Chart

TimP — Thu, 24 May 2018 19:53:02 GMT

Thank you! I was mistaken in thinking that data had to be stacked in order to complete the IR. My data starts split anyway, and this is an ideal solution...thanks for pointing me in the right direction.

Re: How to Get Limits for Capability on IR Control Chart

TimP — Thu, 24 May 2018 19:54:33 GMT

That's a helpful clarification, thank you.