Dimensional Variation Analysis (DVA) Mission

A Group Dedicated to Deploying

Advanced Processes and Tools

in Statistical Tolerance Analysis

for Improved Reliability, Cycle Time,

Comparative Advantage, and ROE.

4 Tier ApproachTier 1; Nom. Clearances & Worst Case (WC) Analysis

&

Tier 3; Monte Carlo Simulation using @Risk

&

Tier 4; VSA/PRO-E 3-D Variation Simulation

Tier 2; Modified WC and RSS Statistical Analysis

# Tolerances

Ass

em

bly

Tole

ran

ce

W/C Reality

RSS

Increasin

g F

irepo

wer

DVA Team Concept

Greg Steinrock & Mike Baker

DVA Team

AHD

Engineering Leader

PDE

Engineering Leader

Class I

Engineering Leader

JEP

Engineering Leader

CTC

Engineering Leader

CEP

Engineering Leader

Class II

Engineering Leader

Signature

Engineering Leader

Standard Graphical User Interface

Tornado Diagram For Tolerance Allocation

Angular Misalignment (Degrees)

CPK= 1.0

Angular Misalignment (Degrees)

CPK= 1.67

Design “No Fly Zone”

Fuel Pump Geometry, GD&T... Assembly, FEA, Wear ...

2.60%

58.04%

1.66%

14.98%

0.94%

2.60%

5.22%

4.13%

1.61%

10.40%

0.00%

0.42%

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7

GEAR OD TOLERANCE (total)

POCKET RAD FORM TOL ("total")

BUSHING BORE DIA TOL (total)

BUSH WALL THICK TOL (total)

SHAFT DIA TOLERANCE (A) (total)

TOTAL GEAR ID TOLERANCE

TRUE POS TOL (FR /RR BUSHINGBORES)

PERP TOL (FR/RR COVERDOWELS)

PERP TOL (CTR DOWEL BORES)

OD/ID GEAR RUN-OUT TOL

SHAFT STRAIGHTNESS TOL (ZoneD; gear area only)

SHAFT STRAIGHTNESS TOL (NonZone D or entire shaft)

DVA Simulation

Add Thermal Effects

Add Structural Effects

Add Wear Effects --> Net Cumulative Distribution

Dimensional Variation

DVA Results

End Clearance

Radial Clearance

Tolerance ReallocationGear Design Change

Nominal Shift

ROBUST FINAL DESIGN

Hydraulic Control Valve

Frequency of Needle Valve Spacer by Part Number

0.00%

5.00%

10.00%

15.00%

20.00%

25.00%

30.00%

35.00%

40.00%

45.00%

50.00%

55.00%

Non

e

Non

e

4010

248

4010

247

3348

586

3348

587

3348

588

New

P/N

?

New

P/N

New

P/N

New

P/N

Non

e

Non

e

Non

e

Non

e

Part Number

Fre

qu

ency

Capability Data

Needle Valve Stop Spacer Frequency of Use By Part Number

0.00%

5.00%

10.00%

15.00%

20.00%

25.00%

30.00%

35.00%

3330

062

3329

822

3329

823

3329

824

3329

825

3329

826

3329

827

3329

828

3329

829

3329

830

3329

831

3329

832

3329

833

3329

834

3329

835

3329

836

3329

837

3329

838

3329

839

3329

840

3329

841

Part Number

Fre

qu

en

cy

Capability Data

Solenoid Spacer

Frequency of Solenoid Spacer by Part Number

0.00%

1.00%

2.00%

3.00%

4.00%

5.00%

6.00%

7.00%

8.00%

9.00%

10.00%

11.00%

12.00%

13.00%

14.00%

Part Number

Capability Data

Questions?