GD&T in SAP (Geometrical Dimensioning and Tolerancing for Results Recording)

[davekatz]

GD&T in SAP

Being in the, Aerospace and Defense, Manufacturing Industry, Customers and Colleagues have enticed me with a question I could not quite answer; “Can you get ‘GD&T’ (or Geometric Dimensioning and Tolerancing) into SAP Results Recording?” After days of trial and error, finally I have an answer, an outstanding “YES!!!”

I hope this instruction finds its way to manufactures in need…

 

Here is how to get GD&T out of SAP;

Starting within an Operation, whether it is in a Routing or an Inspection Plan, create the Basic dimensions and then create the GD&T control frame features. Once complete, test your solution and provide to the customer.

For this example, the Basics are ballooned features 1, 2, 4 & 5 and the Control Frame ballooned features 3 & 6.



 

1. Create the first Basic Characteristic; Set as Quantitative and maintain the Control Indicators.

(“Defects Recording” not activated since Basic dimensions are theoretically exact and cannot be rejected)

2. Enter the Target value, UoM, and Decimal places.


3. Enter Sample Procedure, UoM and Base Qty.


4. Repeat 1-3 for other basic dimension.


5. Create the Control Frame Characteristic; Set as Quantitative and maintain the Control Indicators.

(Select “Cal. Charac.” to enable GD&T Calculations)

6. Enter the Target value, UoM, and Decimal places.


7. Calculate the Control Frame as a Formula. Use the Hot Key to view a list of variable formula parameters to use.
   
   
   
   • On paper this calculation would look like ~ 2 √ ((Deviation of first Basic)²+(Deviation of second Basic)²)
   
   
   • In SAP this calculation would look like = 2*(SQRT(((C70010-A00010)**2)+((C70020-A00020)**2)))
     
     
     
     • Formula interpreter: True Position =2*(SQRT((( ppnnnn – ppnnnn)**2)+((ppnnnn-ppnnnn)**2)))
       
       The variable 'pp' defines the formula parameter and 'nnnn' represents the characteristic from which the value of the formula parameter is taken.
     
     
     • “C7” = Target value of characteristic, “A0”= Measured value for single unit, “SQRT”= √, **= exponent
     
     
     
     
   
   
   
   

8. Maintain the Defect Codes


9. Enter Sample Procedure, UoM and Base Qty.


10. Save and create an Inspection Lot for testing.


11. Enter Basic Dimensions and have SAP Valuate


12. Once valuated select the GD&T characteristic and calculate it by clicking the “Evaluate Formula” icon.


13. Valuate and Save. SAP has calculated GD&T!!!
    
    
    
    • SAP valuates per the parameters and accepts or rejects the feature. The table below was used to ensure it was being calculated properly with different results, as well as, requirements.
    
    
    
    

Record the Usage Decision when ready.

Thank You,

Dave Katz

 

Lessons Learned

I recommend creating a "Preset Control Indicator" for Basic dimensions.

For Basic dimensions, activate “Check target value” control indicator to ensure the target values are not skipped when setting up.

Set the Basics and their applicable GD&T characteristics with the same Sampling procedure, if used.  I prefer to set “Required char.”, "Scope fixed", as well as “Record measured vals” to ensure all results are captured and the GD&T will be able to be calculated.

The first result correlates with each first result. The second result correlates with the second of each and so on. If a Basic result is missed, the GD&T characteristic will not calculate. (Easier to visualize when inspecting serialized material)

Practice makes perfect!!!

Feel free to reach out to me if you have any questions concerns.
Thanks again,

Dave Katz