Introduction to using Crystal Ball 7.0 in the context of Linear Tolerance Stack Ups.

1. Tolerance Stack-ups Using Crystal Ball March 20, 2009

2. The Tolerance Stackup Process (Revised 11/19/2008) Slide 3 Slide 5 Slide 26 Slide 26

3. Get Stackup Template From WindChill 1. Inputs: Part Descriptions & Dimensions 2. Loop Equation (Transfer Function) 3. Output Open file named: TolerStackup Excel’97 ver7.xlt This is a macro-enabled Excel template

4. Associated to CTQ? 2 3 4 5 1 Yes Yes Yes Yes Yes Part or Process Not a CTQ. Consider Worst Case Stack-up No No No No

6. The Tolerance Stackup Process (Revised 11/19/2008) Slide 3 Slide 5

7. CONCATENATE (Text1, Text2,…Text255) The CONCATENATE function joins up to 255 text strings into one text string. The joined items can be text, numbers, cell references, or a combination of those items. For example, if your worksheet contains a person's first name in cell A1 and the person's last name in cell B1 , you can combine the two values in another cell by using the following formula: =CONCATENATE(A1," ",B1) The second argument in this example ( " " ) is a space character. You must specify any spaces or punctuation that you want to appear in the results as an argument that is enclosed in quotation marks.

8. VLOOKUP( Cell, Range, Column#, FALSE ) You can use the VLOOKUP function to search the first column of a range of cells, and then return a value from any cell on the same row of the range. The V in VLOOKUP stands for vertical. Use VLOOKUP instead of HLOOKUP when your comparison values are located in a column to the left of the data that you want to find.

9. Class Exercise: open Excel file named Auto Referencing Exercise 01-MAR-09 B A O Z

10. Create a Unique Identifier on the left column of the Parts Lists

11. Create a Unique Identifier on the left column of the Parts Lists (Copy Down)

12. Create a Unique Identifier on the Left Column of the Loop Equation

13. Create a Unique Identifier on the Left Column of the Loop Equation (Copy Down)

14. Use the Vertical Lookup Function to Auto-populate Your Dimensions

15. Use the Vertical Lookup Function to Auto-populate Your Dimensions Find an EXACT match; don’t leave this blank

18. Using Data Validation to Poka Yoke Entries The selectable choices are limited to the group name fish ; all other categories do not show up. Class Exercise: open Excel file named Data Validation Exercise 01-MAR-09

19. =INDIRECT ( Name of Range ) 1. Select a range of cells 2. Right click mouse 3. Give the range a name 4. Repeat steps 1-3 for the next three Groups ( bird , reptile , fish )

20. =INDIRECT ( Name of Range )

21. =INDIRECT ( Name of Range ) Cell $C$21 = “mammal” By entering the Name of the Range inside the parenthesis of the INDIRECT statement, only the items listed in the Name Range become selectable. Cell $C$21

22. =INDIRECT ( Name of Range ) Cell $C$21 = “mammal” By entering the Name of the Range inside the parenthesis of the INDIRECT statement, only the items listed in the Name Range become selectable.

25. The Tolerance Stackup Process (Revised 11/19/2008) Slide 26 Slide 26 Engineering Non-CTQs CTQs

27. How It Works 1. Transform probability (input) to cumulative probability function 3. Convert random number to sample value 2. Generate a random number between 0 & 1 4. Input sample value to Loop Equation (Transfer Function) 5. Re-calculate Stackup and record simulation result from this trial 6. Generate another random number and repeat the process until you have 10,000 trials

29. 2 Options for Launching Crystal Ball Option 1: Launch automatically every time you open Excel Option 2: Start manually separate from Excel. Choose this option if you’re running Crystal Ball less than 20% of the time you’re running Excel

30. 3 Basic Crystal Ball Components Crystal Ball Term Common Names Assumption Input, X, independent variable, random variable, probability distribution. This is where you enter part dimensions. Decision Variable Controlled variable. Not used in the Stackup Template because there are optimization problems. Forecast Output, Y=f(x), dependent variable. This is where you analyze the result of the Loop Equations (see worksheet tab named STACK-UPS).

31. Open the MS Excel’97-2003 file named: BricardLock Class Exercise 1.0.xls

35. Figure 1. Add process variation to your Excel-based nominal values by clicking the Define Assumption button in Crystal Ball.

37. Figure 2. We have 21 pre-defined distributions in Crystal Ball and 1 custom distribution. Assume the Normal distribution if you do not have any actual data or samples regarding your part.

40. 3 Basic Crystal Ball Edit Functions Crystal Ball Term Common Names Copy an assumption (input) and forecast (output) variables. Copy the distribution parameters, the naming format, and any other CRYSTAL BALL attribute associated with that Cell. Microsoft Excel Cell Values and Formulas are left alone (not affected by this command). Allow you to past CRYSTAL BALL attributes (assumptions and forecasts) into similar cells. You may copy one cell and paste the attribute into many cells in one click; thus, it is the quickest way of defining CRYSTAL BALL components. Removes CRYSTAL BALL components from selected cells, thus making them in-active or deterministic (no variability is associated with the cell).

41. Think of Crystal Ball Entities as layered objects placed on top of Microsoft Excel

42. Think of Crystal Ball Entities as layered objects placed on top of Microsoft Excel Microsoft Excel Objects (Cells, Worksheets, Formulas, etc.) Crystal Ball : Assumptions & Forecast

43. Crystal Ball edit commands only effect Crystal Ball Entities. Cell values, Formulas, and Formatting are un-affected. Microsoft edit commands can copy & paste the green & light blue colors associated Crystal Ball entities, but it will not effect Crystal Ball calculations.

45. Figure 5. COPY & PASTE are the fastest way to define your assumptions.

49. Part Number B520-647: Minitab Capability Study Check for normality

50. Part Number B520-647: Minitab Capability Study Xbar =0.6155 S=0.00073 Cpk=0.24

59. Figure 14. What the finished LOOP EQUATION should look like

61. Figure 15. Defining a forecast entity (output) in Crystal Ball

65. Forecast Charts: What-if? Scenarios

66. Forecast Charts: What-if? Scenarios Enter 0.2800 into this text box and then hit the ENTER key. The Certainty% will update. Question: By how much would the capability improve if I opened up the tolerances to LSL=0 and USL=0.2800? The capability would go up by 1.65% (from 82.65% to 84.30%).

67. Sensitivity Chart: Getting to the Cause of the Problem First, we need to create one. Click the “New” button … Choose your stack-up by name then click OK.

68. Sensitivity Chart: Getting to the Cause of the Problem Question: There are 12 items in my Loop Equation; which one is causing the most variance? The CENTER OF LWR C’BORE TO CENTER OF UPPER C’BORE is causing most of the variance.