TR-0024 Special Characteristics Training for GS-0004Danfoss Power Solutions| 1| 1 Special...

TR-0024 Special Characteristics Training for GS-0004Danfoss Power Solutions | 1

Special Characteristics TrainingGS0400

powersolutions.danfoss.com


Academy special characteristics class - Course options

Course Awareness Competency Mastery

Length 2 hour 4 Hours 8 Hours

Learning•What are they?•Why have them?•How Do They Fit in to PPAP & PDLP?•Who is Responsible?•How do I find them on drawings/Specs?

Awareness +•How to Determine special characteristics•GRR, Capability, SPC requirements•FAQ

Competency +•Loss Functions•S x O = Loss Function•Role of Control Plan, GRR, Capability for different loss functions•Making Good Decision

Roles Team LeadersSupervisors

Design/Process LdrsQuality/Design/Process EngPurchasingIncoming InspectionQuality TechsSupplier QualityIncoming Inspection

All Quality Eng.Some Design Eng.Some Process Eng.Supplier Dev.DFMEA facilitators

Use Controls at Lower Left To select Training level

(Must be in Presentation Mode)


3

D-FMEAGS0003

Process MapGS-0063

Product TestGS0017

Special Char. GS0004

P-FMEAGS0006

Gage R&RGS0010

CapabilityGS0007

Control PlanGS0012

ISIRGS0015

PPAPGS0008

QFDGS0031

Steps to Quality


Agenda

What GS-0004 Covers Purpose Scope & Application Definitions Responsibility Determining Special Characteristics Documentation PPAP and Process Control Requirements

Drawings Created Before GS-0004E Summary/Q&A


What is the purpose of special characteristics?

Focus Special Attention on the “Vital Few” Things which make a Difference to our Customers

Formally Communicate these “Vital Few” Characteristics and their Required Process Controls throughout the Supply Chain

Promote Design For Manufacturability (DFM) through Simultaneous Discussions regarding Design Tolerances and Manufacturing Variation

Aid in Economically Manufacturing Quality Products that meet Customer Expectations

Require Greater Production Control/Monitoring of the “Vital Few” Facilitate Knowledge Management through time (both Product

Engineering & Process Engineering)


What does “Special Attention” mean?

Focused Attention during the Design and Processing Data based Design For Manufacturability (DFM)

Drives Severities from DFMEA into PFMEA Required Levels of Process Capability and Control

Gage R&R, Capability exceeds Features included on Control Plan with appropriate Statistical Controls

Indicate importance of the features throughout the life of the product/process (Knowledge Management)

Ensure Extra attention is made during review of PPAP/Change Management document review


“Vital Few” Aren’t they All important?!

Yes – All we must strive for all features to always be “In Print” Key Characteristics are those characteristics that being “On target with

Minimum Variation” provides better satisfaction than just being “in Print” Features not important for customer safety or satisfaction can be

handled differently for more economical manufacturing Focusing on All is like Focusing on None!


Why “Vital Few”?How many should we have?Lets look at the Loss Function

“Los

s”

Dis-SatisfactionDue to Cost

PerformanceDis-satisfaction

Total ProductDis-Satisfaction

Number ofSpecial Characteristics

0 All


GS-0004 Purpose Scope & Application Definitions Responsibility Determining Special Characteristics Documentation PPAP and Process Control Requirements


Agenda


Scope & Application

GS-0004 Creates Special Characteristics Safety Characteristics Key Characteristics Process Characteristics Standard Characteristics

GS-0004 applies to Danfoss Power Solutions Globally All New Designs

GS-0004 Defines Selection Identification Documentation Required Manufacturing Controls




Agenda


DefinitionSafety Characteristics

Safety characteristics are those characteristics/features which have the potential to affect safety.

When defining safety characteristics the safety of all personnel involved in the product test, vehicle commissioning, and end use of the product need to be considered.

Safety characteristics should be controlled through robust safety margin for normally expected process variation

AND manufacturing error-proofs that detect/prevent abnormal process variation which

could significantly reduce safety margin. Safety characteristics will be identified on the engineering drawing with a

pentagon with an ‘S’ inside it.

S


Definitions

Normally expected process variation The amount of manufacturing variation when the process is maintained under

the defined process controls. Note that for some process controls normally expected variation will include

some out of specification

Safety margin The difference between the extreme of normally expected process variation and

the point at which a safety loss could occur Abnormal process variation

Unusual Manufacturing variation created by a process failure Broken tool, missed heat treatment, etc

Error-proof Device or method which Detects and contains/corrects abnormal variation


Definitions- safety margin

LowerSpecification

Limit

UpperSpecification

Limit

Point at whichSafety is Impacted

Safety Margin

Normally Expected Process Variation

DesignSpecification

Note: Normally Expected Process Variation Shown is for a process with 100% Sort and a GRR of 50%

AbnormalProcess Variation

Examples

http://commons.wikimedia.org/wiki/File:Achtung.png


DefinitionKey characteristics

Key characteristics are defined to be those characteristics for which the normally expected process variation affects product function/customer satisfaction Customer can distinguish product differences due to the variation of a key

characteristic within specification Customer satisfaction is increased when these characteristics are

maintained on target with minimum variation Key Characteristics will be identified on the engineering drawing with a

pentagon with a ‘K’ inside it

K


Definition Process characteristics

Process Characteristics are features/characteristics which do not directlyaffect the function of a product but are important for success of downstream manufacturing processes Tolerances held tighter than needed for product function to accommodate robotic

assembly Internal Customer satisfaction depends on these features being

in specification External Customer Satisfaction (Product Function) does not require the

tolerance to be held this tightly Process characteristics will be identified on the engineering drawing

with a pentagon with a ‘P’ inside it

P


Q: Why did we create a Process CharacteristicA: Some areas do automated assembly. For automated assembly you often

have a robot grabbing the part on a non-functional area and then assembling into a tight clearance

Robot Grabs d2 and installs spool into bore

If Concentricity ( ) of d2 to D1 is not important for function but is necessary forAutomated assembly. Concentricity of d2 to D1 would be a Process Characteristic


EndcapA-B machining operation in a cellbolt holes Machined in A-op and used for location on the B-op.

For the process we need to the holes to be + .1 and a True Position of .1mm

Engineering Drawing (Function) says+.13mm and True Position of .75mm

Should we Modify the Engineering Drawing and Use a P?

No – If it is within your own processes it should be done within your own process controls (e.g. cell control plan/process drawings, etc) Not with the Engineering Drawing

Process Characteristic Example


DefinitionStandard characteristics

The majority of features in a good design are standard features. Standard features must be maintained within specified limits

Standard Features are those for which reasonably anticipated manufacturing variation is unlikely to significantly affect a product’s safety or function

Customer satisfaction does not change based on where a standard feature is within its tolerance range

Standard Features do not have a symbol

No Symbol


Agenda




Responsibility

Product Engineering is responsible for identifying and classifying Safety and Key special characteristics as soon as practical in the design process

Product Engineering Managers in individual areas shall be responsible for ensuring Special characteristics are correctly documented on Engineering drawings and specifications

Process characteristics, if required, are to be identified by Process Engineering

Operations and Purchasing Managers in individual areas shall be responsible for ensuring adequate process controls are put in place for special characteristics


Assigning special characteristics

Design Engineering Assigns Safety and Key Characteristics Utilizing the Design FMEA as soon as possible in the Design Process Safety Characteristics

Severity ≥ 9

Key Characteristics Severity ≥ 5 & Occurrence ≥4

Safety and Key Characteristics Severity ≥ 9 & Occurrence ≥4

Manufacturing Engineering Assigns Process Characteristics


Assigning Safety CharacteristicsWithin propel

Assignment of Safety Characteristics Requires Special Controls

Follow your local BA rules (usually requiring Director of Engineering Approval) before assigning Safety characteristics to drawings.

S


Agenda




Determining Special Characteristics

First Use Design FMEA Severity and Occurrence Ratings Special Characteristics Table

Then Evaluate “Border” cases using Loss Function Method Continuous or Step Loss No Margin, Small Margin, Large Margin “Border Cases” from Severity and Occurrence Table

Covered in “Expert” Training


Determining Special CharacteristicsUsing DFMEA Severity & Occurrence (S x O)


DFMEA SeverityReference GS-0002/HPP 200


DFMEA OccurrenceReference GS-0002


Applying Judgement

In addition to the use of DFMEA Severity and Occurrence, Key characteristics can be determined using the quality loss function logic defined in Appendix ‘C’ of GS0004

Quality Loss Function logic can be an effective way to assess “border” cases from the “S x O” method (i.e. Occurrences of 4,5 & 6 and Severities of 5 and 6) to determine if classification as a “Key” characteristic is really warranted

Engage an expert in Quality Loss functions DFMEA facilitators Quality Engineers


Determining Special CharacteristicsUsing DFMEA Severity & Occurrence (S x O)

Border Cases


Special Characteristics Applied to Material or Heat Treatment Specs

Special Characteristics may be applied to material and heat treatment specifications

Key if DFMEA severity ≥ 5 and occurrence ≥ 4 DO NOT base occurrence (design margins) on an assumption of the

supplier using the wrong material or a required heat treatment is omitted For example: The part will break if the supplier uses the wrong material so I

will make it a Key Characteristic Loss Function Method is a very good for material and heat treatment

Specifications.


Special Characteristics Identified onMaterial or Heat Treatment Specs

The special characteristic must be assigned to something that is measurable (hardness, case depth, tensile strength, etc.) and not to the entire specification

Material: ASTM A536 Grade 65-45-12

Hardness: 156-217 BHN


Agenda




Special Characteristics identified onDanfoss Power Solutions engineering drawings

A pentagon with an “S” for Safety, a pentagon with a “K” for key, or a pentagon with a “P” for process shall be placed on the technical document by each characteristic designated as a special characteristic.



In the case that a feature is described by multiple callouts a special characteristic designation is required for each callout.



In cases where a characteristic is both a safety and a key the special characteristics are to be designated as shown in Fig 3. The order (K first or S first) is not important


Documentation

Add the Note “Special Characteristics per GS-0004” on the first page of the Drawing/Specification

Customer Importance Table (CIT) must be on First Page of all drawings and relevant specifications Typical drawing formats shown Below May be included on other pages

Error-Proof


Special CharacteristicsLocation Table

An Optional Location Table on Sheet 1 defines wherespecial Characteristics are Located Helpful to make sure that none are missed This drawing has 36 Specials Located on 5 Sheets

38

Sheet #Location x QTY


Correctly Showing a Completed Drawingwhich has no Special Characteristics Add the CIT Table to the First Page of the Drawing/Specification even if

there are no Special Characteristics

Add the Note “Special Characteristics per GS-0004” on the first page of the Drawing/Specification

Add the CIT Table and a Blank Special Characteristics Table to the first page of the Drawing/Specification


Agenda




Process Requirements

S, K, &/or P characteristics Must be Identified on PFMEA and Control/Gauging Plan including control method

S Requires Error Proof Control method K Requires Statistical Control Method

Therefore statistical Gage R&R and Capability studies must be completed and exceed minimum requirements

P Does not require a specific control method


Production control methodsAcceptable for safety characteristics

The Manufacturing Focus for Safety Characteristics is to ensure that abnormal variation (i.e. “Special Cause” process failures ) that significantly reduce or eliminate an adequate design margin do not occur

What is a abnormal variation Process Goes out of control and produces “unexpected” variation

S


Definitions- Safety margin

LowerSpecification

Limit

UpperSpecification

Limit

Point at whichSafety is Impacted

Safety Margin


DesignSpecification

Note: Normally Expected Process Variation Shown is for a process with 100% Sort and a GRR of 50%




Example Special causes(Sources of unexpected variation/Abnormal process variation)

Wrong Material/Heat treatment Wrong raw material received / selected Wrong or interrupted heat treatment Doesn’t get to proper temp due to thermal capacitance

Tool Set-up Errors Wrong off-set entered in machine Wrong insert Wrong Radii

Broken Tools/Wrong Tools Broken Fixtures

Bent dowel pins Missing rest pads Note that special cause failures affect all

Parts until corrected.

They can create a BIG problem but they are easier to detect because all parts

are affected


Example special causes(Sources of unexpected variation)

Missed Operations Missed heat treat altogether Missed test / adjustment process

Unplanned process stoppages Delay prior to quench Incomplete operations Machine restart in middle of program

Undetected Maintenance Issues Broken Valves Furnace Filters

Note that special cause failures affect all parts until corrected.

They can create a BIG problem but they are easier to detect because all parts

are affected


Suitable control plans for

Safety characteristics require an Error proof What is an Error proof?

A process or device that ensures either Special cause errors do not take place or If it has occurred, does not allow the next process step to take place or Produces an immediate error signal and corresponding non-conforming

material control in the event of a special cause errors What does an error proof Not do

It is not intended to control common cause (normally expected) variation

S


Establishing good error proofs

1. Understand the ways the process could fail and produceAbnormal variation Fishbone diagram (5M/E) PFMEA

2. Second determine best way to control Error proof types

Type 1 Error-Proof: Prevent from happening Type 2 Error-Proof: Detect before passing from operation Type 3 Error-Proof: Detect at next (or Downstream) operation

S


Example error proof control methods(100% Preventing or detecting unexpected variation)

Wrong material Bars: Each bar verified as loaded in machine properties or color code Castings: Lot material certifications

Wrong or inadequate heat treatment Samples inspected from each lot

Missing heat treatment Inspection at next operation

Broken tools Inspect 1st piece/last piece Broken tool Detection (Laser or Load Monitoring)

Wrong tool/wrong insert/wrong offset Inspect 1st piece Barcode at pre-setter/scan at installation Tool holder only accepts correct insert

Delay before quench IR temperature reading at quench S


Process control requirements

Safety Characteristics / PPAP Requirements Identified as safety on PFMEA & assigned severity = 10 Identified as safety on Control plan with an error proof (Poke-Yoke)

documented on control plan

S



Key characteristic / PPAP requirements Identified as “Key” on PFMEA & Assigned severity = 8 Production control with variable gauging & GR&R<20% completed per GS-0010 Capability studies completed per GS-0007 with capability Cpk > 1.33 Identified as “Key” on control plan (symbol or words) Statistically valid control method which will maintain Cpk>1.33

K


Production control methodAcceptable for key characteristics

Sampling to Reduced Limits Checking every nth piece or samples from a lot to Less than Print LimitsRestudyCapability Study Completed every XX MonthsSetup CheckDefined number of parts checked at Set-upTool ControlFirst and Last Parts checked from ToolTool Changes at Defined Life (# Parts or # Minutes)Modified SPCSampling to Process Limits, Samples Fall within +/- 3 Sigma LimitsShort Run SPCShort Run Statistical Process ControlSPC Control ChartsStatistical Process Control (Xbar and R)

Sampling to Print LimitsChecking Every nth Piece or sample from a lot to Print Limits

Pre-ControlTarget Area Control; 5 Pcs at Set-up 2 Samples to 50% Spec Limits

May be OKIf Short Term (30pc) CapabilityIs High (Cp>2.5) and tool lifeCharacteristics are known/reliableAnd maintains Cpk > 1.33

OK for Any CapabilityAs long as 5 & 2 rule followed

Not OK

K

Ok if MaintainsCpk > 1.33


Process control Requirements

Safety and Key Characteristic Identified as Safety on PFMEA & Assigned Severity = 10 Identified as Safety on Control Plan with an Error Proof (Poke-Yoke)

documented on Control Plan Production Control with Variable Gauging & GR&R<20% completed per GS-0010

(in addition to error proof) Capability Studies Completed per GS-0007 with capability Cpk > 1.33 Statistically Valid Control Method which will maintain Cpk>1.33

(in addition to error proof)



Process characteristic PPAP requirements Identified as “Process” on PFMEA & Assigned severity = 4 Identified as “Process” on Control plan

P

X


Agenda


Drawings created before GS-0004E Summary/Q&A


Comparing revision E toPrevious revisions of GS-0004

Drawings created before GS-0004 Rev E used 2 symbols (Critical and Key) for performance characteristics

GS-0004 Rev E to the standard reduces this to 1

C K=KLegacy drawings createdbefore GS0004 rev E

Interpreted AsGS0004 rev E & after

or


Comparing revision E toPrevious revisions of GS-0004

Also Remember: “border” cases from the “S x O” method (i.e. Occurrences of 4,5 & 6 and Severities of 5 & 6) to determine if

classification as a “Key” characteristic is really warranted.


Agenda

What GS-0004 covers Purpose Scope & application Definitions Responsibility Determining special characteristics Documentation PPAP and process control requirements

Drawings created before GS-0004E Summary/Q&A


Special characteristics summary

Special characteristics are identified by product engineering and process engineering during development and formally documented onengineering drawings, specifications, and control plans

The design FMEA is the basis for determining special characteristics There are 3 kinds of special characteristics

Safety characteristics affecting safety

Key characteristics affecting satisfaction

Process characteristics affecting manufacturing Processes

The purpose of special characteristics is to focus attention on the“Vital Few” characteristics most important for product function &customer satisfaction


Special characteristics summary

Special Characteristics have required levels of process performance and process control that must be validated and documented as part of the PPAP process

Gauging Capability Process Control

Safety Attribute or Variable

No Special Cause Defects

Error Proof

KeyVariable

GRR<20%Cpk>1.33

Statistical Control to Ensure Cpk Maintained

S+KVariable

GRR<20%No Defects & Cpk > 1.33

Error Proof +Statistical Control

Process Not Defined Cpk>1.0 Not Defined


Frequently asked questions list

Why did we change the old Standard? How did we change the old Standard? Why did we create a Safety Characteristic? Why are S’s allowed? Where do we find the Ss and Ks for Assembly and Testing? Do we put S’s or K’s on the product outline drawing? How do we communicate S’s or K’s to customers ? Should ‘K’ be used for Cleanliness? What is the Best Process flow to Follow when Determining K’s and S’s? GS0004 States that the following Severities should be used for PFMEA’s When and to what products do we start to apply the new GS-0004? Do we need to upgrade the old prints/ drawings? How are we going to provide communication /training to suppliers and internal SD o

perations? Is it possible that when updating old drawings through the new process an old “C” c

ould turn into “S”?



Do we have to have a DFMEA to assign Special characteristics? How will this revision lead to fewer Special Characteristics? How Does the Loss Function Help Find the Critical Few? Do we apply Loss Function to “S”? Can we downgrade “S” to “K” by Loss function method? How Do we Quantify “Small” vs. “Large” Margin? How do Design Margin and Safety Margin Relate to each other? Why did the standard change from C & K to only K? What to do with Drawings where the old type of critical marking (bubbles) in case a

im for a supplier change? Why did we create a Process Characteristic? When in the process will Process Characteristics be defined? Can Process Characteristics be defined by process engineering and

not be documented in the drawing? Could we have “K”, which can not be measured by Variable Gages? Actions? Should the “S” and “K” be checked in the receiving inspection?



How Do I interpret Table 4? What is Pre-Control? Will this apply to “Pure-Play” businesses? Do we need to add K’s and S’s to Operator Instructions? How should we update Product Family Drawings? How do we handle customer requests for Keys (or Criticals)? Where do We Document application of Loss Function for “Border Cases”?


Many necessary barriers/improvements were identified Viewed as Propel Standard

Understanding and Buy in of other divisions Confusion about SON

If followed exactly, SON created too many critical/Key Characteristics If a new engineer designs something and can’t make the calculations are

we are supposed put critical characteristics on the drawing??? Too Many characteristics strictly following SON

People wanted the ability to use more judgment No good way to define Safety Criticals and drive the correct type of

control plan Request for Process Criticals for automated assembly purposes not

Product Function

Q1: Why did we change the standard?

A:

Return to FAQ List


Global Team Global Team working over a year with 2 in person meetings Understanding Why and then how Engineering, Quality, Purchasing

Doug McCoy Claus Tjoernly Rasmussen Knud Lange Martin Raadkjaer Joergensen Jeff Baldus

Approving Group/Process Owners Global Engineering

A:

Q2: Who changed the Standard?

Return to FAQ List


A: Our products and their function can impact customer’s safe vehicle operation, if abnormal variation (special cause) happens.

The international legislation (new the Functional Safety Directive EU/2006/45) requires evaluation and notification of safety relevant product miss-function.

Q3: Why did we create a safety characteristic?

Return to FAQ List


A: Yes, Absolutely but it may not be possible in all casesAs part of the approval process for S’s

We do recommend an escalation Process for the “S” approvalthrough Director of Engineering in each BA before adding an “S” to the drawing

Q4: Why are S’s allowed? Should engineering try to eliminate them with design?

Return to FAQ List


A: The Assembly Ss and Ks will be in the AS (Assembly spec)and the Testing Ss and Ks will be in the TS (Test spec)

Q5: Where do we find the Ss and Ks for Assembly and testing?

Return to FAQ List


A: No – They should be noted Product Specification and in technicalliterature not on outline drawings

Exception: Customer Specified Critical Characteristics could be shown on customer specific outline drawings

Q5: Do we put S’s or K’s on the product outlinedrawing?

Return to FAQ List


A: Safety Characteristics are communicated through technical literature. Key Characteristics are communicated through the APQP/PPAP process

Q6: How do we communicate S’s & K’s tocustomers ?

Return to FAQ List


A: Cleanliness follows a continuous loss function but this is alreadyaccounted for in GS-0086 Cleanliness should not be a key characteristic

Q7: Should ‘K’ be used for cleanliness?

Return to FAQ List


A1. DFMEA2. SxO 3. Loss Function to review border cases4. DFM and PFMEA (understand process variation and define “Ps” as necessary)5. Approval for any S’s6. Document on Drawing/Specification7. Define which “S” and “K” go to technical literature (in EC/PPAP Teams w/ TST

representative.

Q8:What is the best process flow to followwhen determining Special Characteristics?

Return to FAQ List


A: GS0004 States that the following Severities should be used for PFMEA’s

Safety: Severity=10Key: Severity=8Process: Severity=4Standard: Severity=4

Severity for the Process FMEA does need to come from the DFMEA. We do not, however, supply DFMEAs to our Suppliers.

By assigning Severity based on the Classification of Characteristics we can do a very good job of transferring the Severity indirectly without providing the DFMEA.

It also provides for a very easy way for the PFMEA to be checked when reviewing the PPAP

Q9: GS0004 Defines the Severities to be used in PFMEAs. Shouldn’t they Come from the DFMEA?

Return to FAQ List


A: April 1, 2010 is the starting point We apply this standard to all new designs (Parts, Components and Final Products) to every EC (Engineering Change)

Q10: When and to what products do we start to apply the new GS-0004?

Return to FAQ List


A: Not as a individual activity of updating all drawings, but if a drawing is going to be EC’d for other reasons then the process(slide 147) will be started also for all legacy products

Q11: Do we need to upgrade the old prints/ drawings?

Return to FAQ List


A: Procurement is responsible for training external suppliers to this standard. Quality is responsible for training internal suppliers to this standard

Q12: How are we going to provide communication/training to suppliers and internal Danfoss Power Solutions operations?

Return to FAQ List


A: Yes, this is possible, when we create / review DFMEA we could identify Severity >9. “S”s created in this way still require approval

Q13: Is it possible that when updating old drawings through the new process an old “C” could turn into “S”?

C S?

Return to FAQ List


Q14: For old drawings we do not even have a DFMEA, do we need to create one, or can we jump directly to the Quality Loss Function?

A: It is greatly preferred/recommended to have a DFMEA.However, if a DFMEA can not be created the Loss Function Methodologycan be used

Return to FAQ List


Also Remember: “border” cases from the “S x O” method (i.e. Occurrences of 4,5 & 6 and Severities of 5 & 6) to determine if

classification as a “Key” characteristic is really warranted.

Return to FAQ List

Q15: How does this compare to previous standards


Q16: How can loss functions help find the critical few

A: Helps to assess border cases from the SxOQuality Loss Method S x O Method

Return to FAQ List


Q17: Do we apply loss function to “S”?

A: No, we apply loss function only for “K” (normal variation and common cause) border cases

Return to FAQ List


Q18: Can we downgrade “S” to “K” by loss function method?

A: No, but through redesign (robust design) we can change the severityrating down to < 9

Return to FAQ List


A: Refer to the GS-0002 DFMEA Occurrence table

82

No Margin

High Margin

Small Margin

Q19: How do we quantify “small” vs. “large” margin?

Return to FAQ List


LowerSpecification

Limit

UpperSpecification

Limit Safety Margin


DesignSpecification

Design Margin

Note: Normally Expected Variation is for a process with 100% Sort and a GRR of 50%

A:

Q20: How do design margin and safetymargin relate to each other?


Return to FAQ List



A: We wanted to reduce the complexity. Reduce the amount of time discussion/ negotiating C or K and reduced process control requirements means reduced costs

C K=KLegacy Drawings CreatedBefore GS0004 Rev E

Interpreted AsGS0004 Rev E & After

or

Q21: Why did we change from C & K to only K

Return to FAQ List


A: The Drawing needs update to the new GS. For the first RFQ the olddrawing can be used, but for each next step (pre-order) an updateddrawing must be used

Q22: What to do with drawings where the old type of critical marking (bubbles) if we change suppliers?

Return to FAQ List


A: Primarly to accommodate automated assembly

For automated assembly you often have a robot grabbing the part on a non-functional area and then assembling into a tight clearance

Robot Grabs d2 and installs spool into bore

If Concentricity ( ) of d2 to D1 is not important for function but is necessary for

Automated assembly. Concentricity of d2 to D1 would be a Process Characteristic.

Q23: Why did we create a Process Characteristic

Return to FAQ List


A: See FAQ 8: In Step 4 after the loss function step

Q24: When in the process will Process Characteristics be defined?

Return to FAQ List


Q25: Can Process Characteristics be defined by process engineering and not be documented in the drawing?

A: Yes, “P” can be in the Control Plan for so called “technological dimensions” or “in-process dimensions”. These are characteristics, which must be “under control” already before the print dimension has been manufactured.

e.g. bearing diameter on the shaft before heat treatment and finishing

“P” on the print /drawing is always a final dimension and is not a “in process” dimension

Return to FAQ List


Q26: What If we have a “K” which can not be measured by Variable Gages?

A: Because we want to keep “K” features “on target with minimum variation” we want to have variable gauges to control them. Attribute gauges onlykeep features “in print”1) First use the loss function method to make sure it should be a Key characteristic 2) During the DFM session see if there are other ways to measure or control

measure the tool not the hole use other feature that can be measured easily and directly correlate to

the key characteristic Discuss it as a team; be creative

3) Attribute gages can be used if the tolerances are reduced from the specification.

if an attribute gage is the only available process control for a key featureyou might consider options like pre-control with “Green” and “Yellow” attribute gages.

Return to FAQ List


Q27: Should the “S” and “K” be checked in the receiving inspection?A: Yes. We focus on “S” and “K” features during DFM and the PPAP process.

During DFM we discussFor all “S” and “K” features the loss function, Capabilities, Gauging, and control plans

During PPAP we approve The suppliers ISIR (all dimensions checked to our print) The Suppliers Control plan (all “P”,”K” and “S” shown) The suppliers Gage R&R and Capability Studies (“K”)

Any new parts should come through Receiving Inspection for the first 3 shipments where “S” and “K” checks would be part of the inspection. If there are no problems the parts can either stay in Receiving Inspection (every shipment or skip lot) or be removed.

Should we see (or suspect) that the supplier is not “in control” we should check “S” and “K” in the receiving inspection as a containment, and also in parallel to work with the supplier to improve the process capability and control.

Return to FAQ List


Pre-control at 50% “Green Zone” and “Print Limits” are referencing the tolerance on the (Design) Engineering Drawing?

If The Engineering Print Tolernace is + 0.1Print Limits = + 0.150% Green Zone is + 0.05

A: “check 1/10 to print limits” means to check every 10th part made to make sure it is “in print”. Note this is not a suitable for Key characteristices

Q28: How do I interpret table 4?

Return to FAQ List


A: “Pre-Control” is a statistically based control method. It is also sometimes referred to as “Target Area Control” The embedded materials provide more information.

Pre-controlPre-control simulation

Q29: What is Pre-control?

Return to FAQ List


Q30: Will this apply to “Stand-Along” businesses (Turolla, Comatrol,…)? A: Non-core business will be able to define there own quality systems

Return to FAQ List


Q:31 Do we need to add K’s and S’s to operator instructions Q:Do they need to be on the operators instructions at the assembly line.

Should it be called out in Standard Work? A:They are required to be called out on the control plan which is different than

the operator method instructions (standard work, Computer screens at workstations, etc.) You may wish to identify K’s and S’s in these documents but it is not required

Return to FAQ List


Q32: Updating product family drawings

If we are developing new frame sizes in a Family using the new Special Characteristics Standard should we go back and change the drawings on the previous frame sizes?

Yes it is recommended; many of these parts will be going through the same manufacturing cells (both internally and externally) this allows us to have common production controls for the family

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Q33: How do we handle customer requests for Keys (or criticals)A: Important first is to understand that we are on the same page. What does the

customer really want:-To be in print for every unit?-Have statistical data about the feature? (especially valve settings is a good example)

-achieve a certain cpk?To obtain a common understanding a long discussion w/ some training elements (GS0004 and GS for PPAP) to be used may be needed. This discussion should involve Product Engineering (in addition to Operations and Quality)

As a result we may have to agree to put a "Key" in, but also change our tolerances at the same time, so we have no need to change the manufacturing process. Change of tolerance can be calculated from cpk=1 to cpk=1.33 easilyChanges to tolerance can affect Test Cycle time and First Pass Yield so it is important to include Operations in the discussion.

Return to FAQ List


Q34: Where do we document application of lossfunction for “Border Cases” A: Best location is inside the D-FMEA where the RPN number is. You can

put a comment into the field how the loss function is looking and the conclusion to leave or take away the key.

Return to FAQ List


Break 15 min


Advanced Special Characteristics Materials

For those needing to know more


Advanced topics agenda

Loss function concept Minimizing losses for a population Examples


How Satisfied would YOU be if the temperature in this room was 22.8C? What would be your loss?

UpperTemperature

Limit

LowerTemperature

Limit

Qua

lity

Los

s(C

usto

mer

Dis

sati

sfac

tion

)

22 ºC71.6 ºF

23 ºC73.4 ºF

21 ºC69.8 ºF

*Completely Satisfied?No Loss

Of Productivity

*Somewhat Dissatisfied?5% Loss

Of Productivity

*Completely Dissatisfied?10% Loss

Of Productivity


What would your satisfaction be over the entire temperature range?

UpperSpecification

Limit

LowerSpecification

Limit

22 ºC71.6 ºF

23 ºC73.4 ºF

21 ºC69.8 ºF

* ** * ** *

**

**

Qua

lity

Los

s(C

usto

mer

Dis

sati

sfac

tion

)

No LossOf Productivity

5% LossOf Productivity



Are you sure it is not like this?

UpperTemperature

Limit

LowerTemperature

Limit

22 ºC71.6 ºF

23 ºC73.4 ºF

21 ºC69.8 ºF

**

** * * * * * * * *

Why Not?

Qua

lity

Los

s(C

usto

mer

Dis

sati

sfac

tion

)





Quality loss function (Taguchi)

Specification Limits

Loss

Target

Taguchi: When a characteristic moves away from a target value increasing loss occurs

Taguchi

Traditional

Traditional:product within specification is all equally “OK”


Is the quality loss function real?

Specification Limits

LossTarget

Taguchi: When a characteristic moves away from a target value increasing loss occurs

Taguchi

Traditional

Traditional:product within specification is all equally “OK”


Quality Loss Function - exampleTaste of your favorite beer?

UpperSpecification

Limit

LowerSpecification

Limit

Normal Toobitter

Toosweet

* ** * ** *

**

**

Qua

lity

Los

s(C

usto

mer

Dis

sati

sfac

tion

)


What about other Loss Functions?Continuous/minimum is best

Qua

lity

Los

s(C

usto

mer

Dis

sati

sfac

tion

)

* ** **

*

*

*On target with

minimum variationproduces lowestamount of loss


Qua

lity

Los

s(C

usto

mer

Dis

sati

sfac

tion

)

** ***

*

*

*

On Target WithMinimum VariationProduces LowestAmount of Loss

What about other loss functions?Continuous/Maximum is best


Quality Loss Function - exampleHow satisfied are you with the cleanliness of a plate in a restaurant?

UpperDirt

LimitNoDirt

Qua

lity

Los

s(C

usto

mer

Dis

sati

sfac

tion

)

Very DirtyClean Normal

* ** **

*

*

*WhichOne?


Quality Loss Function - exampleHow satisfied are you when paying for 20 liters of fuel and getting something different?

20.25

Qua

lity

Los

s(C

usto

mer

Dis

sati

sfac

tion

)

20.0019.75** **

**

*

*

Liters actually delivered

WhichOne?


What would Loss Functions like these mean?Q

uali

ty L

oss

USLNomLSL

Qua

lity

Los

s

USLNomLSL

When this characteristic isJust outside of specification there is a total quality loss (High customer dis-satisfaction)

When this characteristic isfar outside of specificationThere is a small quality loss(Some customer dis-satisfaction)


What would these Loss Functions mean?

Qua

lity

Los

s

USLNomLSL

Qua

lity

Los

s

USLNomLSL

No Loss in Specification

No

Cha

nge

in Q

ualit

y L

oss


What would these Loss Functions mean?Q

uali

ty L

oss

USLNomLSL

Loss when Out of Specification – Low Margin

Qua

lity

Los

s

USLNomLSL

Loss when Out of Specification – High Margin


Classifying Loss Functions

114


Definition:Loss inside specification or outside of specification

Loss Inside of Specification (IN)

Loss outside of specification (Out)


Definition: design margin

Design MarginThe Difference Between The Specification Limit

And Where Noticeable Customer Dissatisfaction (loss) Begins

Large Margin

Small Margin


Definition: Loss slope

Shallow Loss is small near starting point Must vary a lot to be noticed

by most

Steep Loss happens suddenly Noticeable immediately

by Most/All


Classifying Loss Functions

Specification

Margin

Slope

IN OUT

None Small Large

Loss Function

Steep Shallow Steep Shallow Steep Shallow


Using Loss Functions to identify key characteristics

Specification

Margin

Slope

IN OUT

None Small Large

Key Characteristic

May Be Key Characteristics

Standard Characteristics

Loss Function

SteepShallowSteep Shallow Steep Shallow


Comparing SxO method to quality loss method

Continuous

Low Margin

High Margin

Quality Loss SxO Table


Shallo

w

LossSlope

Ste

ep

SxOTable

Comparing SxO method to qualityloss method

Ste

ep

Shallo

wShallo

wShallo

w


Comparing S x O method to qualityloss method

Characteristic Table

Quality Loss Method S x O Method



Loss Function concept Minimizing losses for a population Examples


Losses for a complete population

NormallyExpectedVariation

UpperSpecification

Limit

LowerSpecification

Limit

LossFunction

Tota

l C

usto

mer

Loss


The general case

Total Loss =

dyyLyP )(*)(


Knowing the “Normally expected variation” & the loss function predicts the total loss

Normally expected variation Variation which should be expected produced by the process

operating under control Capabilities Measurement Variation (GRR) Control plan adjustments Tool wear Set-ups Etc


Predicting normally expected (Long Term) variation

Long Term Variation = f ( , , )

How WellWe See

GaugeR&R

(GS 0010)

HowRepeatableShort Term

CapabilityStudy

(GS 0007)

How WeControl &

Adjust

ControlPlan

(GS 0012)

Variation which should be expected produced by the process operating under control.

CapabilitiesMeasurement Variation (GRR)Control plan adjustmentsTool wearSet-ups etc


Creating the model - The Effect of short term (30pc) capability

Short Term Capability Study Cp = 2 Cpk = 2

MaxMin

Is this the Normally Expected

Variation? Why Not?

What About Gage R&R?

Nom


Creating the model - The effect of GRR

“Spread” We See

“Spread” Of Process

“Spread” Of Measurement

ObservedVariation

ActualVariation

MeasurementVariation


Creating the model - Effect of GRR

Short Term Capability Study Cp = 2/Cpk = 2

MaxMin

Is this the Normally Expected

Variation? Why Not?

What About Mean Shifts Over Time?

Nom

Cp/Cpk = 1.46

• Gage R&R - GRR = 40%

Mean Shifts


Creating the model - Effect of control plan on mean shifts

Short Term Capability Cp = 2/Cpk = 2

Measurement Variation GRR = 40%

Mean Shift (Control Plan) Samples To Print

MaxMin Nom

Mean

This is the NormallyExpected Variation!!


Simulation modeling

Model Assumptions

Allowable mean shift determined by Control Plan Check 1/n to print limits Allowable Mean Shift is Specification Pre-Control/Target Zone Control Allowable Mean Shift is Target Zone SPC Allowable mean shift is control limits on Xbar Chart

3s Value determined by Combination of Short Term Capability and GRR S = sqrt(s^2process + s^2measure) alternatively if SPC is used the limits on the Range Chart can be used


Examples

Cp =.8 Control = 100% Inspect 100% GRR

USLLSL

Trapezoidal Distribution

Gage R&R

USLLSL

Over Time


Examples

GRR = 5% Cp = 10 Control: Check 1/10 to Print Set up @ USL/Run to LSL

USLLSL

Time

USLLSL

Square Distribution

Gage R&R


Examples

GRR = 25% Cp= 1.83 SPC with +/- 1.5 Mean Shift

USLLSL

Time

USLLSL

Trapezoidal Distribution

Gage R&R


Long term distribution simulator

Lets Look at a typical scenario for standard features

Control Plan = Samples to print Capability = 1 GRR = 30%

Simulation


Simulation results

Simulation Predicts Parts Can be Made Outside of Specification Limits (Note: Samples will not be shipped Outside of Specification Limits)

0.0160 0.0165 0.0170 0.0175 0.0180 0.0185 0.0190 0.0195 0.0200

LowerSpecLimit

UpperSpecLimit


What distribution would have lowest total quality loss?How can we know?

UpperSpecification

Limit

LowerSpecification

Limit

22 C 23 C21 C

Qua

lity

Los

s(C

usto

mer

Dis

sati

sfac

tion

)





What would be the total loss if the temperature distribution was as shown

UpperSpecification

Limit

LowerSpecification

Limit

22 2321 21.5 22.5

25% 25% 25% 25%

Qua

lity

Los

s(C

usto

mer

Dis

sati

sfac

tion

)




Total Loss

.25*3.5

Total Loss

.25*3.5+.25*0.5

Total Loss

.25*3.5+.25*0.5+.25*0.5

Total Loss

.25*3.5+.25*0.5+.25*0.5+.25*3.5

Total Loss

.25*3.5+.25*0.5+.25*0.5+.25*3.5

Total Loss = 2.0

0.5

3.5

For these simple examples use the loss at the middle of the bar to calculate



UpperSpecification

Limit

LowerSpecification

Limit

22 2321 21.5 22.5

10%

40% 40%

10%

Qua

lity

Los

s(C

usto

mer

Dis

sati

sfac

tion

)




Total Loss

.10*3.5

Total Loss

.10*3.5+.40*0.5

Total Loss

.10*3.5+.40*0.5+.40*0.5

Total Loss

.10*3.5+.40*0.5+.40*0.5+.10*3.5

Total Loss

.10*3.5+.40*0.5+.40*0.5+.10*3.5

Total Loss = 1.1

0.5

3.5



UpperSpecification

Limit

LowerSpecification

Limit

22 2321 21.5 22.5

50% 50%

Qualit

y L

oss

(Cu

sto

mer

Dis

sati

sfa

cti

on

)




Total Loss

.50*0.5

Total Loss

.50*0.5+.50*0.5

Total Loss

.50*0.5+.50*0.5

Total Loss = 0.5

0.5



100% UpperSpecification

Limit

LowerSpecification

Limit

22 2321 21.5 22.5

Qualit

y L

oss

(Cu

sto

mer

Dis

sati

sfa

cti

on

)




Total Loss

1.0*0.0 Total Loss = 0



100%

UpperSpecification

Limit

LowerSpecification

Limit

22 2321 21.5 22.5

Qualit

y L

oss

(Cu

sto

mer

Dis

sati

sfa

cti

on

)




Total Loss

1.0*3.5 Total Loss = 3.5


Quality loss vs. distribution“In specification” loss functions

2.0

1.1

0.5

0.0

On Target With Minimum Variation Produces Lowest

Total Loss for “In Specification” Loss Functions

3.5


Dealing with special characteristics

Continuous Loss Function Design

Data Based Design For Manufacturability (DFM) Manufacturing process control

Maintain Process on Target with Minimum Variation Improve Processes to meet Long Term Capability or Reduce Tolerance

Zone to XX% Use Variable Production Gauging Have Acceptable Gage R&R

Measurement Variation as % of Process Variation is more important than as a % of specification

Run SPC or TAC control Plan Maintain Process On Target with Minimum Variation


What would these Loss Functions mean?

Qualit

y L

oss

USLNomLSL

Qualit

y L

oss

USLNomLSL

Would being on target with minimum variation

improve your satisfaction?

No C

han

ge in

Qu

alit

y L

oss



UpperSpecification

Limit

LowerSpecification

Limit

22 2321 21.5 22.5

25% 25% 25% 25%

Qualit

y L

oss

(Cu

sto

mer

Dis

sati

sfa

cti

on

)

0% Loss

5% Loss

10% Loss

Total Loss

.25*0

Total Loss

.25*0+.25*0

Total Loss

.25*0+.25*0+.25*0

Total Loss

.25*0+.25*0+.25*0+.25*0

Total Loss

.25*0+.25*0+.25*0+.25*0

Total Loss = 0



100% UpperSpecification

Limit

LowerSpecification

Limit

22 2321

21.5 22.5

Qualit

y L

oss

(Cu

sto

mer

Dis

sati

sfa

cti

on

)

No Loss

5% Loss

10% Loss

Total Loss




100%Upper

SpecificationLimit

LowerSpecification

Limit

Qua

lity

Los

s(C

ust

omer

Dis

sati

sfac

tion

)

No Loss

5% Loss

10% Loss

Total Loss

1.0*100% Total Loss = 100


Quality Loss vs. distributionlow margin Loss Functions

All Distributions“In Specification”

Produce Zero Losses0

0

100 Out of SpecificationProduces High Losses



Low Margin Loss Function Design

Design as “Flat” as Possible (Lower DFMEA Severity) Data Based Design For Manufacturability (DFM)

Manufacturing Process Control Variable or attribute gauging 100% Sort/P-Y is OK/Attribute Gage Gage R&R

Measurement Variation as % of Specification Attribute Gage is OK Guard Banding for very low margins Capability

Determines gauging Frequency Important for yield

Control Plan 100% Sort to Spec Limits is OK (with GRR considerations)

Low Margin Loss Function


What Would Be the Total Loss if the Temperature Distribution was as Shown

152

UpperSpecification

Limit

LowerSpecification

Limit

25% 25% 25% 25%

Qua

lity

Los

s(C

usto

mer

Dis

sati

sfac

tion

)

0% Loss

5% Loss

10% Loss

Total Loss

.25*0

Total Loss

.25*0+.25*0

Total Loss

.25*0+.25*0+.25*0

Total Loss

.25*0+.25*0+.25*0+.25*0

Total Loss

.25*0+.25*0+.25*0+.25*0

Total Loss = 0



153

100%Upper

SpecificationLimit

LowerSpecification

Limit

Qua

lity

Los

s(C

usto

mer

Dis

sati

sfac

tion

)

No Loss

5% Loss

10% Loss

Total Loss




154

100%UpperSpecification

Limit

LowerSpecification

Limit

Qua

lity

Los

s(C

usto

mer

Dis

sati

sfac

tion

)

No Loss

5% Loss

10% Loss

Total Loss

1.0*0 Total Loss = 0%



155

100%UpperSpecification

Limit

LowerSpecification

Limit

Qua

lity

Los

s(C

usto

mer

Dis

sati

sfac

tion

)

No Loss

5% Loss

10% Loss

Large Special Cause(s)is needed to produce

Customer Losses


Quality Loss vs. distributionhigh margin loss functions

All Distributions“In Specification”

Produce Zero Losses

0

0

0Out of Specification

“Common Cause” VariationProduces No Losses



High Margin Loss Functions Design – Good Job! Manufacturing Process Control

Gage R&R No formal studies needed. Any good measurement system needs to have variation

less than 30% of Specification Capability

No Formal Study needed Cpk >1

Control Plan Process control which ensures there are no Special Causes which

cause an abnormal process shift large enough so that a loss will occur First/Last Piece Checks Set up verification + Tool Life/Broken tool reaction etc

High Margin Loss Function


Production control summary

“In specification” Loss Function Minimum loss if “On target with minimum variation”

Capability, GRR, Control Plan define expected variation Capability Improvement for better customer satisfaction

100% Sort is not acceptable long term; containment only

“Small Margin” Loss Function No loss as long as “in Specification” 100% sorting OK if capability bad Capability improvements for scrap reduction GRR important if sorting

Large Margin Loss Functions No loss unless there is “unexpected variation” due to process going out of

control Focus on controlling assignable causes through PFMEA and Error-Proof Consider increasing tolerance for scrap reduction Simple controls (1st Piece/last piece, broken tool detection, etc)



Loss Function Concept Minimizing Losses for a Population Examples


Special characteristics using Loss FunctionExample 1: 25.00 +/- .02 is spool diameter

1) Determine the customer loss(es) As Diameter (D1) gets bigger

Leakage decreases probability of stiction increases

As Diameter gets smaller Leakage increases probability of stiction decreases

2) Determine where losses begin Leakage changes with diameter (clearance) throughout tolerance Stiction/hysterisis change throughout tolerance

3) Select type of Loss Function Continuous Loss Function Steep slope


Special characteristics using FMEA methodExample 1: 25.00 +/- .02 is Spool diameter

Severity

Occurrence

DFMEA SEVERITY

DFMEA OCCURRENCE



Specification

Margin

Slope

IN OUT

None Small Large

Key Characteristic



LOSS FUNCTION



Is it a special characteristic?


Example Loss FunctionExample 2: 25.00 +/- .02 is clearance hole

Determine the Customer Loss(es) As Hole Gets Smaller

Pin Won’t Go Through Hole Product Won’t Function

As Hole Gets Larger Stress in part increases

2) Determine where losses begin Pin Might Not Go Through Hole at 24.98 Stress is not a concern until Hole is 28.5

3) Select Type of Loss Function Low Margin Loss Function Steep Slope


Using loss functions to identify key characteristics

Specification

Margin

Slope

IN OUT

None Small Large

Key Characteristic



LOSS FUNCTION



Example FMEAExample 2: 25.00 +/- .02 is Clearance hole

Severity

Occurrence

DFMEA SEVERITY

DFMEA OCCURRENCE


Is it a special characteristic???



Specification

Margin

Slope

IN OUT

None Small Large

Key Characteristic



LOSS FUNCTION


RedesignOpportunities


Redesign?Example 2: 25.00 +/- .02 is clearance hole

Maybe?

Redesign!

StressFit


After RedesignExample 2: 25.00 +/- .02 is Clearance hole

Severity

Occurrence

DFMEA SEVERITY

DFMEA OCCURRENCE


Is it a Special Characteristic???


Example Loss FunctionExample 3: 25.00 +/- .02 is Shaft Diameter Determine the Customer Loss(es)

As Diameter Gets Bigger Stress Decreases Coupling Won’t Go on Shaft

As Diameter Gets Smaller Stress increases

2) Determine where losses begin Coupling Does not assemble when Diameter is 25.15 Stress is too high when Diameter is below 24.5

3) Select Type of Loss Function High Margin Loss Function Steep Slope


Example Loss FunctionExample 4: 25.00 +/- .02 is shaft diameter

Determine the customer loss(es)

Determine where losses begin

Select type of Loss Function


Example 3: 25.00 +/- .02 is Shaft Diameter

Severity

Occurrence

DFMEA SEVERITY

DFMEA OCCURRENCE


Is it a Special Characteristic???


Finish!

Thanks for your attention!


Change History

Slide 51 “Production Control MethodAcceptable for Key Characteristics” :added “And maintains Cpk > 1.33” to yellow box

Slide 63 “FAQ 5” :added “product” to outline drawing description. Slide : removed “Propel EU Internal Training for Purchasing /SQA and

Operations will be offered by Eckhard Skirde and Marina Nissen in Q1 2010”

Added new FAQ’s Changed “Border Areas” slides to be correct 15 Oct 2013: changed logo and coloring on slides

Date post:	30-Mar-2015
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