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Referring user defined column in script

medini_1065960298

Hello All,

I have created user-defined column in Design FMEA sheet and now I want to refer them in customization.

I have created a second column for Detection, named "Detection 2". I am trying to calculate RPN 2 with customization, using this new detection no.

How can I use detection 2 for calculating the new RPN no.?

TIA.

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medini_1024169437

Hi Kepin,

it depends a bit how and for which class you define dthe column, the FMEA worksheet has quite a number of types involved. Did you use the Project Settings -> Profiling tool? If so, into which classes did you put your attributes?

Jan

medini_1065960298

Hello Jan,

Thank you for your reply.

I did use Profiling tool to define a different detection and RPN. I defined it under "Current Design Control (derived FMEA and SWA only)".

Is that correct?

Thanks,

Kepin

medini_1024169437

I am not sure Kepin, the current RPN is defined at the MeasureEntry level. Maybe better place it there?

Happy Scripting

Jan

medini_1065960298

Hello Jan,

I do not see any MeasureEntry level. I see Measure, Measure Group, and Measure/Mechanism Collection in Profiling.

Am I missing something?

Kepin

medini_1024169437

Kepin, you are right,

I need to check myself, maybe I was pointing you in the wrong direction.

Jan

medini_1063548292

Hi Kepin,

I will kindly jump in as I replied to similar question in another article.

I can confirm that you choose correct MetaClass to define the detection2.

Once you will define your profile property You can access it from within another Profile property at the same MetaClass using sef.user_detection2 or from FMEA Failure Cause self.currentDesignControls.user_detection2 ( this will work only for OCL).

It will depend where you will pace your RPN2 . I would recommended to really keep it under Current Design Control (derived FMEA and SWA only)

And some example for the JS RPN2 derived profile property formulae

self.user_detection2*self.failureCause.failureMode.maxSeverity*self.occurrence

Note: I would personally define the deteciton2 as a String with predefined values ( from 0- 10) to limit the user input creativity and will introduce a nice drop down list box in the FMEA table editor

Marian

medini_1065960298

Hello Marian,

I tried your recommendation out and it is working.

Thank you

Kepin

medini_1065960298

I have another question.

We are trying to define RPN for the life cycle of the product too. I want to derive Occurrence 2 from the FIT rate of the component.

E.g.,

Occurrence FIT rate

1 0.01 to 0.1 FIT

2 0.100001 to 1 FIT

so on...

Is it possible to define a column in this manner?

Thanks,

Kepin

medini_1063548292

HI Kepin,

It is absolutely possible. Here is the example if one would like to derive custom occurrence based on the FIT rate of FMEA Component's related element, in the example the occurrence is expected to be set based on following:

FIT	<0.1	<0.2	<0.3	<0.4	<0.4	<0.5	<0.6	<0.7	<0.8	<0.9	≥0.9
occ	0	1	2	3	4	5	6	7	8	9	10

Note: FMEA Component can contained Element or a function depending on the preset of the FMEA worksheet therefore if it is a Function a FIT is taken from its owning Element.

I have prepared 2 snippets one for OCL and for JS.

- Both derived properties defined at Current Design Controls

JS:

//navigate form design controls up to the component’s element: Can be Function or HW element
var ele = self.failureCause.failureMode.component.element;
//check if itis sysml if not get owner ( In case it is an Function)
ele = ele instanceof Metamodel.sysml.SysMLPart ? ele:ele.the_owner;
//define limits for FIT corresponding to occ [0,.....9]
var limits = [0.1, 0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9,1.0]
var res = limits.filter( function checkFits(lim) {
					return lim > ele.failureRate;
					})
//substracting the length of arrays will give occurrence 
	limits.length-res.length

OCL:

let
-- define local variable to store componenets' contaiend element
frEle:ecore::EObject= self.failureCause.failureMode.component.element,
-- store fvalue of Fit rate ( check it is HW element of sometning else (Function)
frVal:Real =
		if frEle.oclIsKindOf(sysml::SysMLPart) then
				frEle.oclAsType(sysml::SysMLPart).failureRate
 else 
		 	if frEle.eContainer()<> null then
			 	-- get owner -> using econtainer
 	 frEle.eContainer().oclAsType(sysml::SysMLPart).failureRate
 else 
 	--unexpected case,put something in 
				 0.0
 endif
		endif,

-- define FIT thresholds with resulting occ {0,1,2,3,4,5,6,7,8,9} anything hat is above limits in thesequencewill gte ratingof 10
fitLimits:Sequence(Real)= Sequence{0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9,1.0}
in
if not frVal.oclIsInvalid() then 
--make a comparisons for frVal< limit and return filtered sequence
--get the occurrence value 10 - X , where x will be 10 for fit < 0.1, and 0 for FIT > = 1.0
fitLimits->size() - fitLimits->select(e|frVal<e)->size()
else 
--invlaid frValue ,put some default
0
endif

I cannot fully comment on which one is best for performance (OCL or JS) I will let others to comment

Marian

medini_1065960298

Hello Marian,

Thanks a lot! This is really helpful.

I see that these codes refer to the FIT rates from the Total Failure Rate of the part instead of the Failure Rate Fraction of a particular part.

I tried to change the script to refer to the Failure Rate Fraction instead of the Total Failure Rate. Can you help me identify the variable I am supposed to use to refer to Failure Rate Fraction?

Thanks,

Kepin

medini_1063548292

Hi Kepin,

now I am not sure to understand what is tha value yu want to get..

Can you be more specific? The Fraction in FIT() is present only at failure cause or failure mode and those failure modes are usually contained within part.

Are we talking about FIT of :

Associated FMEA Failure Cause
Associated Failure mode in FMEA
Associated FMEA component
Associated FMEA components FIT relative to FIT summed across all modules of analyzed HW Model
FIT Percentage from parent

Marian

medini_1065960298

Hello Marian,

Thank you for your reply.

Here is the screenshot from my DFMEA -

I have enabled FMEDA columns in the DFMEA, enabling me to see FIT rates in the DFMEA worksheet.

The script is currently referring to the column "Failure Rate (in FIT)", which is circled in red. I want the script to refer to the "Failure Rate Fraction (in FIT)", which is circled in blue.

Does this help in understanding my request?

Thanks,

Kepin

medini_1063548292

Thanks Kepin!

Yes now I understand.

.And to get this value you want it is very easy peasy lemon squeezy ...

OCL

let
-- define local variable to store fitRate value form FailuremMode
frEle:ecore::EObject= self.failureCause.failureMode.element,
 frVal:Real = if frEle.oclIsKindOf(safety::FailureMode) then
 						frEle.oclAsType(safety::FailureMode).failureRate
 else if frEle.oclIsKindOf(safety::Malfunction) then
 	 frEle.oclAsType(safety::Malfunction).failureRate
 	 else 
 	 0.0
 	 endif
 endif,

-- define FIT tresholds with resulting occ {0,1,2,3,4,5,6,7,8,9}
 fitLimits:Sequence(Real)= Sequence{0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9,1.0}
in
if not frVal.oclIsInvalid() then 
--make a comparisons for frVal< limit and return filtered sequence
--get the occurence value 10 - X , where x will be 10 for fit < 0.1, and 0 for FIT > 1.1
fitLimits->size() - fitLimits->select(e|frVal<e)->size()
else 
100
endif

var ele = self.failureCause.failureMode.element;
//chekc ifit is FialureMode or Malfunciton only those support FailureRate
ele = ele instanceof Metamodel.safetyModel.Malfunction || ele instanceof Metamodel.safetyModel.FailureMode? ele:0.0;
//define limits for FIT corresponding to occ [0,.....9]
var limits = [0.1, 0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9,1.0]
var res = limits.filter( function checkFits(lim) {
					return lim > ele.failureRate;
					})
//the calue is bigger then someof deifned limits
if (res.length > 0 ) {
	//return index => occurrence based on the index of the first mathcing limit
	limits.indexOf(res[0]);
} else {
//tooo big FIT set 10 forexample 
10 
}

Happy Rating,

Marian

medini_1065960298

Hello Marian,

Thank you so much for the help!

Regards,

Kepin

medini_1065960298

Hello,

I have implemented the occurrence number based on the FIT rate. I would like to add another condition:

If the potential failure mode involves only latent faults, the occurrence number should be one level lower than what the FIT rate suggests.

Is it possible to add this customization?

Thanks,

Kepin