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Critical To Quality. Using the voice of the customer to measure Quality. Translate Consumer Requirements to Part CTQ Characteristics Step 1 - Understand Consumer & Technical Requirements Step 2 - Translate Technical Requirements to Part CTQ
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Critical To Quality Using the voice of the customer to measure Quality Jina Jayanetti
Translate Consumer Requirements to Part CTQ Characteristics Step 1 - Understand Consumer & Technical Requirements Step 2 - Translate Technical Requirements to Part CTQ Step 3 - Determine how capable we are of meeting requirements Understand Consumer Requirements Customer Expectations Y (Output) Establish measurable testing method Define Technical Requirements What Parts are Affected? Determine parts effected and X’s (Input) CTQ Characteristics (How are they affected?) Establish dimension of part that effect the Technical requirements (Y) Are we capable? Measure parts; establish capability, calculate Z-score Driving decisions with data, not opinion Jina Jayanetti
Critical To Quality (CTQ) Flowdown Voice of Customer Function Parts Dimensions Capability Match Capability vs. goal Launch Jina Jayanetti
Key Terms • KPIV • Key process input variable • Associated with the X’s • KPOV • Key process output variable or Customer requirement • Associated with the Y’s Understand the X’s - control the Y’s Jina Jayanetti
A Grate Example CTQ Flow Down In action Jina Jayanetti
Marketing C.U. Customers Sales Engineering MCS Finger Flatness Base Flatness Top Flatness Target=0 USL=.040” Target=0 USL=.040” Target=0 USL=.040” CTQ Flow Down Voice of the Customer Pots should be stable on the surface Grate Fingers and Base should be flat and parallel within 0.040” Technical Requirements Part Drawings Grate and Main Top CTQ Characteristics Jina Jayanetti
Capability and Z-score Cp Answers the question “Are the specifications matched to the variation in the process?” Formula: Upper Spec - Lower Spec / 6*Std Dev Cpk Answers the question “How well does the process meet the specification?” Formula: Minimum Lower Cp & Upper Cp Lower Cp = Mean - Lower Spec / 3* Std Dev Upper Cp = Upper Spec - Mean / 3*Std Dev (Pp and Ppk are calculated the exact same way, except for the standard deviation number. They use an “inflated” standard deviation to account for changes over time.) How does this relate to Z-score? Z short term = 3 * Cpk Z long term = 3 * Ppk (or Zst - 1.5) Status - “Green” if Ppk > 1.33 (Zlt > 4.0) “Yellow” if 1.33<Ppk < 1.0 (4.0 < Zlt < 3.0) “Red” if Ppk < 1.0 (Zlt < 3.0) Jina Jayanetti
Scorecard Inputs Data Type Codes: A=Expert Opinion B=Similar Process C=Existing Part D=1st Shot from Tooling E=PPAP F=Production Part Jina Jayanetti
Z PPM 2 308,537 3 66,807 4 6,210 5 233 6 3.4 Process Capability Defects per Million Opportunity Scorecard Calculations Cpk Ppk ZLT Status Action Supplier Part Number Critical Characteristic PI 7512P123-60 Grate Dimension Finger Flatness 2.22 1.37 4.10 Green Review with Supplier; investigate Dimension Base Flatness 0.74 0.11 0.34 Red opportunities to reduce variation. Status - Green if Zlt>=4.0 Yellow if 4.0<Zlt < 3.0 Red if Zlt < 3.0 Jina Jayanetti
Concept Concept Development & Volume Total Product Delivery (TPD) Generation Feasibility Implementation Production Transition Concept to Consumer Critical To Quality Flowdown (CTQ) Marketing Introduction Process (MIP) Product Innovation Process (PIP) Request (PCR) Product Change Design for Six Sigma Tools Changes from • Pugh Concept Selection • CTQ Flowdown • QFD • Concept Design • Process Mapping • Process FMEA • Measurement Systems Analysis • Capability Assessment • Statistical Tolerancing • Design for Manufacture • Hypothesis Testing • Design of Experiments • Robust Design Techniques • Control Plans • Measurement Systems Analysis • Multi-Vari Studies • Capability Assessment • Empirical Tolerancing • Hypothesis Testing • Design of Experiments • Robust Design Techniques • Reliability Assessment • Control Plans • Process Control Methods • Design FMEA • Measurement Systems Analysis • Capability Assessment • Statistical Tolerancing • Design for Manufacture • Hypothesis Testing • Design of Experiments • Response Surface Methods • Robust Design Techniques Product Development Process (PDP) Other Areas Gate Review Gate Review Gate Review QFD / CTQ Flowdown • Translate VOC into • Technical Requirements • Identify the Critical Characteristics that contribute to the Technical requirements • Measure Process Capability for each Critical Characteristic • Compare Capability (Ppk) to Cp and determine status • Critical Characteristics verified and control plans/data collection plans developed • Critical Characteristics verified with production data and control plans/data collection plans in place • Identify Voice • of the customer • Look for knowledge of technical requirements (collect tribal knowledge) Jina Jayanetti
CTQ What it is, What it is Not • What it is • Brings disciplined approach to a Quality score card that measures quality prior to product launch • Identifies quality issues • What it is not • Does not correct quality issues • A replacement of sound technical judgment. • A replacement of sound financial discipline. Jina Jayanetti
Key Findings • Current product drawings require deeper detail specifications. • Beginning of the learning curve on process capability and control. • Create a closer relationship with departments that provide VOC information. Jina Jayanetti