Special Characteristics Training GS0400

Special Characteristics Training GS0400
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Academy special characteristics class - Course options
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 Leaders Supervisors Design/Process Ldrs Quality/Design/Process Eng Purchasing Incoming Inspection Quality Techs Supplier Quality 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)

Steps to Quality Product Test PPAP ISIR Control Plan Capability
GS0017 PPAP GS0008 Steps to Quality ISIR GS0015 Control Plan GS0012 Capability GS0007 Gage R&R GS0010 P-FMEA GS0006 Process Map GS-0063 The Slide has builds which are presenter controlled. This chart shows the Danfoss Quality Tools and Standards. The key points about this slide is that the Critical/Key characteristics are coming from the D-FMEA and customer input from the QFD (Quality Function Deployment). The critical/key characteristics are the places where the quality standards of Gage R&R, Capability, and Control Plans are focused. Special Char. GS0004 D-FMEA GS0003 QFD GS0031

Agenda What GS-0004 Covers Drawings Created Before GS-0004E
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!

Special Characteristics
Why “Vital Few”? How many should we have? Lets look at the Loss Function Total Product Dis-Satisfaction Dis-Satisfaction Due to Cost “Loss” Performance Dis-satisfaction All Number of Special Characteristics

Agenda GS-0004 Drawings Created Before GS-0004E Summary/Q&A Purpose
Scope & Application Definitions Responsibility Determining Special Characteristics Documentation PPAP and Process Control Requirements Drawings Created Before GS-0004E Summary/Q&A

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

Definition Safety 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 Safety margin
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
Point at which Safety is Impacted Lower Specification Limit Upper Specification Limit Design Specification Safety Margin Abnormal Process Variation Examples Normally Expected Process Variation Note: Normally Expected Process Variation Shown is for a process with 100% Sort and a GRR of 50%

Definition Key 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 directly affect 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

Robot Grabs d2 and installs spool into bore
Q: Why did we create a Process Characteristic A: 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 for Automated assembly. Concentricity of d2 to D1 would be a Process Characteristic

Process Characteristic Example
Endcap A-B machining operation in a cell bolt 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

Definition Standard 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

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 Characteristics Within 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

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 Characteristics Using DFMEA Severity & Occurrence (S x O)

DFMEA Severity Reference GS-0002/HPP 200

DFMEA Occurrence Reference 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 Characteristics Using 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 on Material or Heat Treatment Specs
Material: ASTM A536 Grade Hardness: BHN The special characteristic must be assigned to something that is measurable (hardness, case depth, tensile strength, etc.) and not to the entire specification

Special Characteristics identified on Danfoss Power Solutions engineering drawings
This is an example to show how- on all new Danfoss drawings – Safety and key Characteristics will be called out. 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 Characteristics Location Table
Sheet # Location x QTY Special Characteristics Location Table An Optional Location Table on Sheet 1 defines where special Characteristics are Located Helpful to make sure that none are missed This drawing has 36 Specials Located on 5 Sheets

Correctly Showing a Completed Drawing which 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

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 methods Acceptable 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 Would checking 1 part/ hour to print limits ensure that we are getting 33 or 3.4 DPM? S

Definitions- Safety margin
Point at which Safety is Impacted Lower Specification Limit Upper Specification Limit Design Specification Safety Margin Normally Expected Process Variation Abnormal Process Variation Note: Normally Expected Process Variation Shown is for a process with 100% Sort and a GRR of 50%

Note that special cause failures affect all
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
Understand the ways the process could fail and produce Abnormal variation Fishbone diagram (5M/E) PFMEA 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 method Acceptable for key characteristics
Sampling to Print Limits Checking Every nth Piece or sample from a lot to Print Limits Not OK Sampling to Reduced Limits Checking every nth piece or samples from a lot to Less than Print Limits Restudy Capability Study Completed every XX Months Setup Check Defined number of parts checked at Set-up Tool Control First and Last Parts checked from Tool Tool Changes at Defined Life (# Parts or # Minutes) Modified SPC Sampling to Process Limits, Samples Fall within +/- 3 Sigma Limits Short Run SPC Short Run Statistical Process Control SPC Control Charts Statistical Process Control (Xbar and R) May be OK If Short Term (30pc) Capability Is High (Cp>2.5) and tool life Characteristics are known/reliable And maintains Cpk > 1.33 Would checking 1 part/ hour to print limits ensure that we are getting 33 or 3.4 DPM? Ok if Maintains Cpk > 1.33 Pre-Control Target Area Control; 5 Pcs at Set-up 2 Samples to 50% Spec Limits OK for Any Capability As long as 5 & 2 rule followed

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 (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 X P

Agenda GS-0004 Drawings created before GS-0004E Summary/Q&A Purpose
Scope & Application Definitions Responsibility Determining Special Characteristics Documentation PPAP and Process Control Requirements Drawings created before GS-0004E Summary/Q&A

Comparing revision E to Previous 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 K = or Legacy drawings created before GS0004 rev E Interpreted As GS0004 rev E & after

Comparing revision E to Previous 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 Drawings created before GS-0004E
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 on engineering 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 Key Variable GRR<20% Cpk>1.33 Statistical Control to Ensure Cpk Maintained S+K No Defects & Cpk > 1.33 Error Proof + Statistical Control Process Not Defined Cpk>1.0

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 operations? Is it possible that when updating old drawings through the new process an old “C” could 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 aim 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”?

Q1: Why did we change the standard?
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 Return to FAQ List

Q2: Who changed the Standard?
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 Return to FAQ List

Q3: Why did we create a safety characteristic?
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. Return to FAQ List

Q4: Why are S’s allowed? Should engineering try to eliminate them with design? A: Yes, Absolutely but it may not be possible in all cases As part of the approval process for S’s We do recommend an escalation Process for the “S” approval through Director of Engineering in each BA before adding an “S” to the drawing Return to FAQ List

Q5: Where do we find the Ss and Ks for Assembly and testing?
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) Return to FAQ List

Q5: Do we put S’s or K’s on the product outline drawing?
A: No – They should be noted Product Specification and in technical literature not on outline drawings Exception: Customer Specified Critical Characteristics could be shown on customer specific outline drawings Return to FAQ List

Q6: How do we communicate S’s & K’s to customers ?
A: Safety Characteristics are communicated through technical literature. Key Characteristics are communicated through the APQP/PPAP process Return to FAQ List

Q7: Should ‘K’ be used for cleanliness?
A: Cleanliness follows a continuous loss function but this is already accounted for in GS Cleanliness should not be a key characteristic Return to FAQ List

Q8:What is the best process flow to follow when determining Special Characteristics?
DFMEA SxO Loss Function to review border cases DFM and PFMEA (understand process variation and define “Ps” as necessary) Approval for any S’s Document on Drawing/Specification Define which “S” and “K” go to technical literature (in EC/PPAP Teams w/ TST representative. Return to FAQ List

Q9: GS0004 Defines the Severities to be used in PFMEAs
Q9: GS0004 Defines the Severities to be used in PFMEAs. Shouldn’t they Come from the DFMEA? A: GS0004 States that the following Severities should be used for PFMEA’s Safety: Severity=10 Key: Severity=8 Process: Severity=4 Standard: 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 Return to FAQ List

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

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

Q12: How are we going to provide communication/training to suppliers and internal Danfoss Power Solutions operations? A: Procurement is responsible for training external suppliers to this standard. Quality is responsible for training internal suppliers to this standard Return to FAQ List

Q13: Is it possible that when updating old drawings through the new process an old “C” could turn into “S”? A: Yes, this is possible, when we create / review DFMEA we could identify Severity >9. “S”s created in this way still require approval 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 Methodology can be used Return to FAQ List

Q15: How does this compare to previous standards
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

Q16: How can loss functions help find the critical few
A: Helps to assess border cases from the SxO Quality 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 severity rating down to < 9 Return to FAQ List

A: Refer to the GS-0002 DFMEA Occurrence table
Q19: How do we quantify “small” vs. “large” margin? A: Refer to the GS-0002 DFMEA Occurrence table No Margin Small Margin High Margin Return to FAQ List

Q20: How do design margin and safety margin relate to each other?
Lower Specification Limit Upper Specification Limit Safety Margin Design Specification Design Margin Normally Expected Process Variation Abnormal Process Variation Note: Normally Expected Variation is for a process with 100% Sort and a GRR of 50% Return to FAQ List

Legacy Drawings Created
Q21: Why did we change from C & K to only K 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 K = or Legacy Drawings Created Before GS0004 Rev E Interpreted As GS0004 Rev E & After Return to FAQ List

Q22: What to do with drawings where the old type of critical marking (bubbles) if we change suppliers? A: The Drawing needs update to the new GS. For the first RFQ the old drawing can be used, but for each next step (pre-order) an updated drawing must be used Return to FAQ List

Robot Grabs d2 and installs spool into bore
Q23: Why did we create a Process Characteristic 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. Return to FAQ List

Q24: When in the process will Process Characteristics be defined?
A: See FAQ 8: In Step 4 after the loss function step 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 only keep 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 feature you 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 discuss For 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

Q28: How do I interpret table 4?
Pre-control at 50% “Green Zone” and “Print Limits” are referencing the tolerance on the (Design) Engineering Drawing? If The Engineering Print Tolernace is + 0.1 Print Limits = + 0.1 50% Green Zone is 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 Return to FAQ List

Q29: What is Pre-control? 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. 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 Return to FAQ List

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 easily Changes 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 loss function 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

Completely Dissatisfied? Somewhat Dissatisfied?
How Satisfied would YOU be if the temperature in this room was 22.8C? What would be your loss? Upper Temperature Limit Lower Temperature Limit * Completely Dissatisfied? 10% Loss Of Productivity 22 ºC 71.6 ºF 23 ºC 73.4 ºF 21 ºC 69.8 ºF Quality Loss * Somewhat Dissatisfied? 5% Loss Of Productivity (Customer Dissatisfaction) * Completely Satisfied? No Loss Of Productivity

What would your satisfaction be over the entire temperature range?
Lower Specification Limit Upper Specification Limit * No Loss Of Productivity 5% Loss Of Productivity 10% Loss Quality Loss (Customer Dissatisfaction) 21 ºC 69.8 ºF 22 ºC 71.6 ºF 23 ºC 73.4 ºF

Are you sure it is not like this?
Quality Loss (Customer Dissatisfaction) No Loss Of Productivity 5% Loss Of Productivity 10% Loss Lower Temperature Limit Upper Temperature Limit * * * Why Not? 21 ºC 69.8 ºF 22 ºC 71.6 ºF 23 ºC 73.4 ºF

Quality loss function (Taguchi)
Traditional Traditional: product within specification is all equally “OK” Taguchi: When a characteristic moves away from a target value increasing loss occurs Taguchi Loss Target Specification Limits

Is the quality loss function real?
Traditional Traditional: product within specification is all equally “OK” Taguchi: When a characteristic moves away from a target value increasing loss occurs Taguchi Target Loss Specification Limits

Quality Loss Function - example Taste of your favorite beer?
Lower Specification Limit Upper Specification Limit * Quality Loss (Customer Dissatisfaction) Too sweet Normal Too bitter

What about other Loss Functions? Continuous/minimum is best
On target with minimum variation produces lowest amount of loss * Quality Loss * (Customer Dissatisfaction) * * * * * *

(Customer Dissatisfaction)
What about other loss functions? Continuous/Maximum is best On Target With Minimum Variation Produces Lowest Amount of Loss * Quality Loss * (Customer Dissatisfaction) * * * * * *

Quality Loss Function - example How satisfied are you with the cleanliness of a plate in a restaurant? Upper Dirt Limit No Dirt * Which One? Quality Loss (Customer Dissatisfaction) Very Dirty Clean Normal

Quality Loss Function - example How satisfied are you when paying for 20 liters of fuel and getting something different? Which One? * Quality Loss (Customer Dissatisfaction) 19.75 20.00 20.25 Liters actually delivered

What would Loss Functions like these mean?
When this characteristic is Just outside of specification there is a total quality loss (High customer dis-satisfaction) Quality Loss LSL Nom USL When this characteristic is far outside of specification There is a small quality loss (Some customer dis-satisfaction) Quality Loss LSL Nom USL

What would these Loss Functions mean?
Quality Loss LSL Nom USL No Change in Quality Loss No Loss in Specification Quality Loss LSL Nom USL

Quality Loss LSL Nom USL Loss when Out of Specification – Low Margin Quality Loss LSL Nom USL Loss when Out of Specification – High Margin

Classifying Loss Functions

Definition: Loss inside specification or outside of specification
Loss Inside of Specification (IN) Loss outside of specification (Out)

Definition: design margin
The Difference Between The Specification Limit And Where Noticeable Customer Dissatisfaction (loss) Begins Small Margin Large 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 IN OUT Margin None Small Large Slope Steep Shallow Steep Shallow Steep Shallow

Using Loss Functions to identify key characteristics
Specification IN OUT Margin None Small Large Slope Steep Shallow Steep Shallow Steep Shallow Key Characteristic May Be Key Characteristics Standard Characteristics

Comparing SxO method to quality loss method
Table Quality Loss Continuous Low Margin High Margin

Comparing SxO method to quality loss method
Table Loss Slope Steep Steep Shallow Shallow Shallow Shallow

Comparing S x O method to quality loss method

Loss Function concept Minimizing losses for a population Examples

Losses for a complete population
Lower Specification Limit Upper Specification Limit Loss Function Normally Expected Variation        Total Customer Loss                            

The general case Total Loss =

Knowing the “Normally expected variation” & the loss function predicts the total loss
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 Well We See Gauge R&R (GS 0010) How Repeatable Short Term Capability Study (GS 0007) How We Control & Adjust Control Plan (GS 0012) Variation which should be expected produced by the process operating under control. Capabilities Measurement Variation (GRR) Control plan adjustments Tool wear Set-ups etc

Creating the model - The Effect of short term (30pc) capability
Short Term Capability Study Cp = 2 Cpk = 2 Is this the Normally Expected Variation? Why Not? Max Min Nom What About Gage R&R?

Creating the model - The effect of GRR
“Spread” We See Observed Variation “Spread” Of Process “Spread” Of Measurement This Slide is now showing the names that are associated with the boxes. The Spread of the process is characterized by “Cp Actual”. Red + yellow = Orange Note that the Orange distribution is wider than either of the two distributions it is made up of (Red and yellow). Actual Variation Measurement Variation

Creating the model - Effect of GRR
Short Term Capability Study Cp = 2/Cpk = 2 Cp/Cpk = 1.46 Gage R&R - GRR = 40% Is this the Normally Expected Variation? Why Not? Mean Shifts Max Min Nom What About Mean Shifts Over Time?

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 Mean Max Min Nom This is the Normally Expected 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 USL LSL USL LSL Over Time Gage R&R Trapezoidal Distribution
Cp =.8 Control = 100% Inspect 100% GRR Gage R&R USL LSL Over Time

Examples Square Distribution USL LSL Time Gage R&R USL LSL GRR = 5%
Cp = 10 Control: Check 1/10 to Print Set USL/Run to LSL Gage R&R LSL USL Time

Trapezoidal Distribution
Examples USL LSL Trapezoidal Distribution Gage R&R GRR = 25% Cp= 1.83 SPC with +/- 1.5 Mean Shift LSL USL Time

Long term distribution simulator
Lets Look at a typical scenario for standard features Control Plan = Samples to print Capability = 1 GRR = 30%

Simulation results Lower Spec Limit Upper Spec Limit Simulation Predicts Parts Can be Made Outside of Specification Limits (Note: Samples will not be shipped Outside of Specification Limits)

What distribution would have lowest total quality loss? How can we know? Quality Loss (Customer Dissatisfaction) No Loss Of Productivity 5% Loss Of Productivity 10% Loss Lower Specification Limit Upper Specification Limit 21 C 22 C 23 C

What would be the total loss if the temperature distribution was as shown Quality Loss (Customer Dissatisfaction) No Loss Of Productivity 5% Loss Of Productivity 10% Loss Total Loss .25*3.5 +.25*0.5 Total Loss .25*3.5 +.25*0.5 Total Loss .25*3.5 Total Loss .25*3.5 +.25*0.5 +.25*3.5 Total Loss .25*3.5 +.25*0.5 +.25*3.5 Total Loss = 2.0 Lower Specification Limit Upper Specification Limit For these simple examples use the loss at the middle of the bar to calculate 3.5 25% 25% 25% 25% 0.5 21 21.5 22 22.5 23

What would be the total loss if the temperature distribution was as shown Total Loss .10*3.5 +.40*0.5 +.10*3.5 Total Loss = 1.1 Total Loss .10*3.5 +.40*0.5 Total Loss .10*3.5 Total Loss .10*3.5 +.40*0.5 Total Loss .10*3.5 +.40*0.5 +.10*3.5 Quality Loss (Customer Dissatisfaction) No Loss Of Productivity 5% Loss Of Productivity 10% Loss Lower Specification Limit Upper Specification Limit 40% 40% 3.5 10% 10% 0.5 21 21.5 22 22.5 23

What would be the total loss if the temperature distribution was as shown Total Loss .50*0.5 +.50*0.5 Total Loss = 0.5 Total Loss .50*0.5 +.50*0.5 Total Loss .50*0.5 Quality Loss (Customer Dissatisfaction) No Loss Of Productivity 5% Loss Of Productivity 10% Loss Lower Specification Limit Upper Specification Limit 50% 50% 0.5 21 21.5 22 22.5 23

What would be the total loss if the temperature distribution was as shown 100% Quality Loss (Customer Dissatisfaction) No Loss Of Productivity 5% Loss Of Productivity 10% Loss Lower Specification Limit Upper Specification Limit Total Loss 1.0*0.0 Total Loss = 0 21 21.5 22 22.5 23

What would be the total loss if the temperature distribution was as shown Quality Loss (Customer Dissatisfaction) No Loss Of Productivity 5% Loss Of Productivity 10% Loss 100% Lower Specification Limit Upper Specification Limit Total Loss 1.0*3.5 Total Loss = 3.5 21 21.5 22 22.5 23

Quality loss vs. distribution “In specification” loss functions
2.0 1.1 0.5 On Target With Minimum Variation Produces Lowest Total Loss for “In Specification” Loss Functions 0.0 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

Quality Loss LSL Nom USL No Change in Quality Loss Would being on target with minimum variation improve your satisfaction? Quality Loss LSL Nom USL

What would be the total loss if the temperature distribution was as shown Quality Loss (Customer Dissatisfaction) 0% Loss 5% Loss 10% Loss Total Loss .25*0 +.25*0 Total Loss .25*0 Total Loss .25*0 +.25*0 Total Loss .25*0 +.25*0 Total Loss .25*0 +.25*0 Total Loss = 0 Lower Specification Limit Upper Specification Limit 25% 25% 25% 25% 21 21.5 22 22.5 23

What would be the total loss if the temperature distribution was as shown 100% Quality Loss (Customer Dissatisfaction) No Loss 5% Loss 10% Loss Lower Specification Limit Upper Specification Limit Total Loss 1.0*0.0 Total Loss = 0 21 21.5 22 22.5 23

What would be the total loss if the temperature distribution was as shown 100% Quality Loss (Customer Dissatisfaction) No Loss 5% Loss 10% Loss Lower Specification Limit Upper Specification Limit Total Loss 1.0*100% Total Loss = 100

Quality Loss vs. distribution low margin Loss Functions
All Distributions “In Specification” Produce Zero Losses 100 Out of Specification Produces 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 Total Loss .25*0 +.25*0 Total Loss = 0 Quality Loss (Customer Dissatisfaction) 0% Loss 5% Loss 10% Loss Lower Specification Limit Total Loss .25*0 +.25*0 Total Loss .25*0 +.25*0 Total Loss .25*0 +.25*0 Total Loss .25*0 Upper Specification Limit 25% 25% 25% 25%

100% What Would Be the Total Loss if the Temperature Distribution was as Shown Quality Loss (Customer Dissatisfaction) No Loss 5% Loss 10% Loss Lower Specification Limit Upper Specification Limit Total Loss 1.0*0.0 Total Loss = 0

100% What Would Be the Total Loss if the Temperature Distribution was as Shown Quality Loss (Customer Dissatisfaction) No Loss 5% Loss 10% Loss Lower Specification Limit Upper Specification Limit Total Loss 1.0*0 Total Loss = 0%

100% What Would Be the Total Loss if the Temperature Distribution was as Shown Quality Loss (Customer Dissatisfaction) No Loss 5% Loss 10% Loss Lower Specification Limit Upper Specification Limit Large Special Cause(s) is needed to produce Customer Losses

Quality Loss vs. distribution high margin loss functions
All Distributions “In Specification” Produce Zero Losses Out of Specification “Common Cause” Variation Produces No Losses

High Margin Loss Function 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

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 Function Example 1: 25. 00 +/-
Special characteristics using Loss Function Example 1: /- .02 is spool diameter 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

DFMEA SEVERITY DFMEA OCCURRENCE
Special characteristics using FMEA method Example 1: /- .02 is Spool diameter DFMEA SEVERITY DFMEA OCCURRENCE Severity Occurrence

Specification IN OUT Margin None Small Large Slope Steep Shallow Steep Shallow Steep Shallow Key Characteristic May Be Key Characteristics Standard Characteristics

Is it a special characteristic?

Example Loss Function Example 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 IN OUT Margin None Small Large Slope Steep Shallow Steep Shallow Steep Shallow May Be Key Characteristics Standard Characteristics Key Characteristic

Example FMEA Example 2: 25.00 +/- .02 is Clearance hole
DFMEA SEVERITY DFMEA OCCURRENCE Severity Occurrence

Is it a special characteristic???

Redesign Opportunities LOSS FUNCTION Specification IN OUT Margin None Small Large Slope Steep Shallow Steep Shallow Steep Shallow Key Characteristic May Be Key Characteristics Standard Characteristics

Redesign? Example 2: 25.00 +/- .02 is clearance hole
Maybe? Fit Stress Redesign!

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

Is it a Special Characteristic???

Example Loss Function Example 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 Function Example 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

Is it a Special Characteristic???

Thanks for your attention!
Finish! Thanks for your attention!

Change History Slide 51 “Production Control Method Acceptable 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 Q ” Added new FAQ’s Changed “Border Areas” slides to be correct 15 Oct 2013: changed logo and coloring on slides

Special Characteristics Training GS0400

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