Inspection & Quality Control
A complete engineering reference for inspection and quality: handheld measuring tools, CMM, optical measurement, hardness testing, NDT, SPC, Gage R&R, AQL sampling, calibration, incoming QC, and quality management standards — with live calculators for Cpk, Gage R&R, TUR, DPMO, AQL, and Sine Bar.
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Inspection & Quality Control
Measuring Tools · CMM · NDT · SPC · Gage R&R · Calibration · AQL · Quality Standards
📏 Handheld Measuring Instruments
Vernier Caliper
±0.02-0.05mmVersatile
Range0-150 / 0-200 / 0-300mm
Resolution0.02mm (vernier) · 0.01mm (digital)
Accuracy±0.02-0.05mm (JIS B7507)
Measurementsoutside · inside · depth · step
TypesAnalog / Digital / Dial / Carbon Fiber
Outside Micrometer
±0.004mmIT6-IT7
Range0-25, 25-50... every 25mm (up to 3000mm)
Resolution0.001mm · 0.0001mm (digital)
Accuracy±0.002-0.004mm
Spindle Pitch0.5mm — one turn = 0.5mm
Measuring Force5-10N (Ratchet Thimble)
Inside Micrometer / Bore Gauge
IT7-IT8Precision Bores
Tubular Inside Mic5-210mm, ±0.005mm
Bore Gauge (dial)6-450mm, ±0.003mm
Telescoping Gauge8-150mm, transfer to micrometer
3-Point Bore Mic±0.001mm — highest precision
Dial Indicator / DTI
0.001-0.01mmRunout · Flatness
Dial Indicatorrange 0-10mm · resolution 0.01mm
DTI (Test Indicator)range ±0.8mm · resolution 0.001mm
Digital Indicatorresolution 0.001/0.0005mm
ApplicationsRunout · Flatness · Parallelism · Setup
Height Gauge
±0.02mmGranite Table
Range0-300 / 600 / 1000mm
Resolution0.001mm (digital)
Accuracy±0.02-0.04mm
Usemarking · height measurement · Datum plane
Gauge Blocks / Slip Gauges
Grade K/0/1/2Reference Standard
Grade K±0.05μm — primary master
Grade 0±0.1μm — instrument calibration
Grade 1±0.2μm — tool reference
Grade 2±0.5μm — shop floor
MaterialsSteel / Carbide / Ceramic
Go/NoGo Gauges — Limit Gauges
Go ✓NoGo ✗IT6-IT9
Plug Gaugehole measurement — Go must enter
Ring Gaugeshaft measurement — Go must pass over
Thread Pluginternal thread — 6H common
Thread Ringexternal thread — 6g common
Gauge PrecisionIT4-IT5 (≈10% of part tolerance)
Taylor Principle: Go checks all dimensions together!
Manufacturers: Dorsey Metrology · Marposs · Telegage
Manufacturers: Dorsey Metrology · Marposs · Telegage
Specialty Gauges
Thread · Radius · Feeler
Feeler Gauge0.05-1.0mm · engine/valve gaps
Radius GaugeR1-R25mm · checking corners/fillets
Thread Pitch Gaugeidentifying ISO/UNC/UNF thread pitch
Pin Gaugeø0.1-13mm · checking holes/gaps
Angle Gauge±1' accuracy · cutting angles
| Measuring Tool | Range | Resolution | Typical Accuracy | IT Grade | Suited For |
|---|---|---|---|---|---|
| Vernier — Caliper | 0-300mm | 0.01mm | ±0.03mm | IT10-IT12 | quick general measurement |
| Micrometer | 0-25mm+ | 0.001mm | ±0.004mm | IT6-IT8 | critical diameter/thickness |
| Dial Indicator | 0-10mm | 0.01mm | ±0.01mm | — | Runout, Flatness |
| DTI (Test Indicator) | ±0.8mm | 0.001mm | ±0.003mm | — | precise Setup, CMM |
| Bore Gauge | 6-450mm | 0.001mm | ±0.003mm | IT7-IT8 | precision holes |
| Height Gauge | 0-1000mm | 0.001mm | ±0.02mm | IT9-IT10 | height, Datum |
| Gauge Block | 0.5-100mm | 0.0001mm | ±0.0001mm | Grade K-2 | reference, tool calibration |
| Go/NoGo Gauge | fixed | — | IT4-IT5 | IT6-IT9 | volume production |
📏 Advanced Measurement Tools
Sine Bar / Sine Plate
±5" angle accuracywith Gauge Blocks
Principlesin(θ) = H / L (L=100 or 200mm)
Accuracy±5 arc-seconds (~0.0014°)
Usesetting precise angles for grinding/inspection
H = L × sin(θ)build height H with Gauge Blocks
Compound Sinetwo axes — compound angles
Air Gauge — Pneumatic
±0.0002mmWall Averaging
Principleair pressure ↔ gap → measurement
Resolution0.0001-0.001mm
Speedinstant! automatic circumferential average
Back Pressurepressure version — for deep holes
Useengine bores, precision drilling, mass production
Optical Flat
λ/20 = 0.03μmInterference Fringes
PrincipleNewton's rings — each fringe = λ/2 ≈ 0.3μm
Light SourceSodium D (589nm) — monochromatic
Tool FlatnessGauge Block / lapped surface
Interpretationstraight fringes=flat · curved=convex/concave
Precision Level
0.02mm/mMachine Alignment
Spirit Level0.02-0.1mm/m · bubble
Electronic Level0.001mm/m · digital resolution
Autocollimator0.1" arc · angular change over range
Uselathe alignment · CMM · press · rails
Roundness Tester
Roundness · Cylindricity0.01μm
Principlerotating part + fixed Stylus
Resolution0.01μm (10 nm)
RoundnessRONt = maximum peak-to-valley
FiltersUPR (Undulations Per Revolution) 1-500
StandardISO 12181
Coordinate Rule + Setup Measurement
V-Block · Magnetic Base
V-Blockshaft stabilization for rotation/measurement
Magnetic Baseattaches to steel · flexible arm
Parallel Barsprecise elevation in pairs · Grade B
1-2-3 Block1"×2"×3" · quick Datum setup
Angle Plateprecise 90° to Surface Plate
Thread Measurement by Three-Wire Method
±0.001mmVerification — ISO 3'Inspection, not production
Principle3 precise (identical) wires placed in the thread grooves — the outer distance over the 2 side wires is measured with a micrometer
Purposemeasuring Pitch Diameter (d2) — the most critical thread parameter
Formula (optimal wire)GW = 0.5774 × P (for 60° metric/UN threads)
Calculating d2M = measurement over wires · d2 = M − 3×GW + 0.866×P
Equipmentcalibrated outside micrometer + set of Thread Wires sized to the pitch
Wire Selection Rulethe wire must contact the Pitch Line — wrong diameter = systematic measurement error!
When to use: verification/calibration of precision threads (Class 3A/3B, aerospace), checking taps and certified master threads, when no Go/NoGo Thread Gauge is available or an exact numerical value is required (not just Pass/Fail).
Advantage over Go/NoGo: gives an actual d2 value (for SPC trends, FAI documentation) — not just pass/fail.
Precision: the most accurate manual method for measuring pitch diameter — also used to calibrate Thread Gauges themselves in metrology labs.
Standards: ISO 3161 / ASME B1.16M / ASME B1.2 (Three-Wire Method) · standard GW tables exist for every pitch.
▶ YouTube
Advantage over Go/NoGo: gives an actual d2 value (for SPC trends, FAI documentation) — not just pass/fail.
Precision: the most accurate manual method for measuring pitch diameter — also used to calibrate Thread Gauges themselves in metrology labs.
Standards: ISO 3161 / ASME B1.16M / ASME B1.2 (Three-Wire Method) · standard GW tables exist for every pitch.
📌 Golden Rule for Measuring Tool Selection:
Tool accuracy ≤ 10% of the measured tolerance (Golden Rule of Metrology)
Example: tolerance ±0.05mm → tool accuracy ≤ ±0.005mm → micrometer (±0.004mm) ✅
Vernier (±0.03mm) = 60% of tolerance → ❌ not sufficient!
Tool accuracy ≤ 10% of the measured tolerance (Golden Rule of Metrology)
Example: tolerance ±0.05mm → tool accuracy ≤ ±0.005mm → micrometer (±0.004mm) ✅
Vernier (±0.03mm) = 60% of tolerance → ❌ not sufficient!
🤖 CMM — Coordinate Measuring Machine
Bridge CMM (Fixed)
±0.002-0.005mmIT4-IT6
AccuracyMPEE = 1.5+L/333 μm (typical)
Touch ProbeRenishaw TP20/TP200 · ball 1-6mm
Scanning ProbeSP25/LSP-X5 · continuous scanning
Operating Temp.20°C ±1°C! (extended with correction)
SoftwarePC-DMIS · Calypso · Quindos · Aberlink
ISO 10360-2: MPEE and MPEP test
Let the part soak 4h before measuring, ±2°C/h change max!
Manufacturers: Zeiss · Hexagon · Mitutoyo CMM
▶ YouTubeLet the part soak 4h before measuring, ±2°C/h change max!
Manufacturers: Zeiss · Hexagon · Mitutoyo CMM
Portable CMM — Measuring Arm
±0.02-0.05mmFlexible
FARO Armrange 1.2-3.7m · ±0.024-0.064mm
ROMER Arm±0.028-0.054mm · 6/7 DOF
Cimcore±0.018mm (comparable)
Advantagemeasure on the floor/machine · portable
▶ YouTube3D Scanner
±0.03-0.1mmReverse Engineering
Structured Light±0.03mm · fast · GOM ATOS
Laser Triangulation±0.05mm · flexible · Creaform
HandySCAN±0.025mm · handheld and portable
CT Scanning±0.005mm · sees inside the part! · Zeiss VoluMax
▶ YouTubeFAI — First Article Inspection
AS9102Aerospace
StandardAS9102 Rev B (aerospace) / PPAP (automotive)
Full FAIevery dimension on the drawing (100%)
Partial FAIcritical dimensions only
DocumentationFAIR Form 1/2/3 · Ballooned Drawing
GD&T Measurement — Geometric Tolerances
ISO 1101ASME Y14.5
Flatnesssurface scan → Least Squares Plane
Cylindricitycylinder scan → three deviations
PositionTP = 2√(Δx²+Δy²) from the Datum
True PositionMMC Bonus Tolerance calculated by CMM
RunoutTotal vs Circular Runout
▶ YouTubeSurface Plate — Granite Table
Grade A/B/CSurface Reference
Grade A (Lab)flatness ±0.001mm/300mm
Grade B (Tool Room)±0.002mm/300mm
Grade C (Shop)±0.004mm/300mm
MaterialBlack Granite (Diabase) — 0 Thermal
🤖 CMM — Advanced Topics
Probe Qualification
Before every measurementDatum Sphere
Reference SphereRuby Sphere ø10-25mm, Grade 5
Number of Pointsminimum 25 points for calibration
PD (Probe Diameter)calculated effective diameter · not actual diameter!
Form Error≤ 0.001mm → valid calibration
Calibration Frequencyevery startup · after collision · after warm-up
Changing Stylus → calibration mandatory!
Styli: Ruby (general) / Silicon Nitride (fast) / Zirconia (Al)
▶ YouTubeStyli: Ruby (general) / Silicon Nitride (fast) / Zirconia (Al)
Datum Reference Frame — DRF
3-2-1 SetupPrimary/Secondary/Tertiary
Primary Datumplane (3 points) → constrains Z/Rx/Ry
Secondary Datumaxis/edge (2 points) → X/Rz
Tertiary Datumpoint (1) → Y
BF vs. ConstrainedBest Fit vs. Datum Locked
Fixturemechanical stabilization = accuracy + repeatability
DRF = GD&T drawing → must represent the drawing's Datum!
Temperature Compensation
20°C ±1°CCTE Correction
StandardISO 1 = 20°C reference
Error per 1°CSteel: 12μm/m · Al: 23μm/m
Temp. SensorsCMM + part + gap
Software CorrectionαΔT×L → automatic correction
Soak Time4h minimum for large steel parts
Al part at 25°C → error 75μm/m — critical!
CTE steel: 11.5μm/m·°C | Al: 23μm/m·°C | Invar: 1.5μm/m·°C
CTE steel: 11.5μm/m·°C | Al: 23μm/m·°C | Invar: 1.5μm/m·°C
PC-DMIS / Calypso — CMM Programming
Offline ProgrammingCAD Import
CAD ImportSTEP/IGES → exported from CAD software
Auto Pathautomatic probe path from CAD
GD&T Auto Evalautomatic Position/Flatness calculation
SPC Integrationexport to Q-DAS / Minitab
CMM ReportPDF/Excel with Balloon Numbers
▶ YouTubeScanning Probe
↑↑speedContinuous vs. Point
Touch Triggerpoint → point · fast for discrete points
Analog Scanning1000+ points/second · Surface Form
Renishaw REVO5-Axis · scans in any direction · ↑↑speed
Scanning AdvantageForm Error · Waviness · free-form curves
REVO = 5-axis rotating head → ↓measurement time 85%
Manufacturer: Renishaw
▶ YouTubeManufacturer: Renishaw
CT Scanning — Industrial Tomography
X-Ray 3DSees Inside!
Accuracy±0.005-0.02mm (depends on VOX size)
Porosity Detectionvoids from 0.1mm · AM castings
Wall Thicknessfull wall thickness map
Assembly CTinspecting closed complex assemblies
Limitationdense/large parts — ↓penetration
▶ YouTube✦ Surface Texture Measurement
Profilometer — Surface Roughness Tester
Ra · Rz · RtContact/Non-Contact
Raarithmetic mean — most common
Rz5-peak average — ISO 4287
Rtmaximum peak to valley
Rq (RMS)root mean square
Stylus radius2μm (conventional) / 0.5μm (micro)
Cutoff λc0.08/0.25/0.8/2.5/8mm (ISO 4288)
▶ YouTubeTypical Ra by Process
Reference Values
Rough TurningRa 12.5-50 μm
Rough MillingRa 3.2-12.5 μm
Finish MillingRa 0.8-3.2 μm
Surface GrindingRa 0.2-0.8 μm
HoningRa 0.1-0.4 μm (Cross-hatch)
LappingRa 0.01-0.1 μm
SuperfinishingRa <0.05 μm
Non-Contact Surface
Optical↑Fast
White Light Interferometryresolution 0.1nm! · Zygo · Bruker
Focus Variation±0.1μm · Alicona InfiniteFocus
Confocal±0.5μm · Olympus LEXT
Fringe ProjectionGOM ATOS · large field
▶ YouTubeN-Grade — Finish Rating
N1-N12
N1Ra 0.025 μm — ↑↑ expensive
N4Ra 0.2 μm — finish grinding
N6Ra 0.8 μm — finish milling
N8Ra 3.2 μm — standard milling
N10Ra 12.5 μm — rough
N12Ra 50 μm — scraping
✦ Advanced Surface Parameters
Waviness vs. Roughness vs. Form
ISO 4287 / ISO 12780
Formlong-wavelength errors — Flatness, Straightness
Waviness Wmedium — Wt, Wa, Wz (λf - λc)
Roughness Rshort — Ra, Rz, Rt (λs - λc)
Cutoff λcseparates Roughness/Waviness
λs0.0025mm — fine roughness filter
Form → Waviness → Roughness: three independent measurement layers!
▶ YouTubeAbbott-Firestone — Bearing Ratio Curve
Bearing RatioRpk / Rk / Rvk
Rk (Core)core profile height — main bearing region
Rpkprotruding peaks — worn away first
Rvkoil valleys — retains lubrication
Rmr (Tp)bearing percentage at a given height
Engine cylinders: low Rpk + high Rvk = ↑life + ↓wear
Standard: ISO 13565-2
▶ YouTubeStandard: ISO 13565-2
Rsk · Rku — Profile Shape
Skewness · Kurtosis
Rsk (Skewness)0=symmetric · + = peaks · - = valleys
Negative Rsk↑bearing area · ↑engine cylinder life
Rku (Kurtosis)3=normal · >3 = sharp peaks
Honed cylinder: Rsk = -1.5 to -0.5 (ideal)
Areal 3D — Three-Dimensional Parameters
ISO 25178Sa · Sz · Sp
Saareal arithmetic mean (like Ra in 3D)
Sqareal root mean square (RMS)
Szmaximum surface height
SdrDeveloped Surface Ratio — bonding
SdqRMS slope — predicts friction
ISO 25178 = the future of measurement! Gradually replacing Ra/Rz
Manufacturers: Alicona · Zygo · Keyence VK
▶ YouTubeManufacturers: Alicona · Zygo · Keyence VK
Comparison Specimens
Tactile ReferenceContact
VDI 3400EDM standard — 45 grades (VDI 12-45)
ISO 2632comparison by process (turning/milling/grinding)
Usequick field/shop check without an instrument
▶ YouTubeSurface Finish by Application
Design Guidelines
Rolling BearingsRa 0.1-0.4 μm · Roundness <1μm
O-ring SealsRa 0.4-0.8 μm · no machining marks!
Hard CoatingRa ≤ 0.8 before coating (EN/Chrome)
Fatigue StrengthRa ≤ 0.4 → ↑30% fatigue strength!
Bonding/CoatingRa 1.6-3.2 → aims for high Sdr
Mark direction ⊥ to load = ↑fatigue strength (Lay Symbol)
🔭 Optical & Laser Measurement
Profile Projector / Optical Comparator
×10 ×20 ×50±0.005mm
Magnification×10, ×20, ×50, ×100
Measurement Accuracy±0.003-0.005mm
Screenø250/500mm · template comparison
DROdigital X/Y/Z · angles
▶ YouTubeVMM — Video Measuring Machine
±0.002mmNon-Contact
Accuracy±0.002-0.005mm
Z-Axis Range150-300mm
Telecentric Lensno Parallax Error
Auto Edge Detection↑speed · ↓operator error
▶ YouTubeLaser Micrometer
±0.001mmNon-Contact · Fast
Principlelaser beam shadowing — Shadow Method
Resolution0.0001-0.001mm
Speedup to 1200 measurements/second!
Useproduction lines, wire, extruded plastic
▶ YouTubeLaser Tracker
±0.025mmLarge Parts
Accuracy±0.016-0.025mm over meters!
Rangeup to 80 meters
SMRSpherically Mounted Retroreflector
Useaircraft · structures · machine alignment
Manufacturers: FARO Laser Tracker · Leica AT960
▶ YouTube🔭 Advanced Optical Measurement
Machine Vision / AOI
Inline100% Inspection
AOIAutomated Optical Inspection — PCB/SMD
Camera Resolution5-50 MPx · Telecentric Lens
LightingCoaxial / Ring / Dark Field / Structured
Speedup to 10,000 parts/hour
AI / Deep Learningdefect detection ↑ ↓False Reject
▶ YouTubePhotogrammetry
±0.05mmVery Large Parts
Principlemultiple photos → 3D points
Accuracy1:100,000 of range
Range1m up to a full aircraft/ship!
Coded Targetsreference markers printed on the part
Scale Barreference bar for scale
Manufacturers: Aicon (Hexagon) · V-STARS (Geodetic)
▶ YouTubeLaser Interferometer
λ/2 = 316nmMachine Calibration
Accuracy0.001μm (1nm) — highest accuracy!
UseCNC/CMM calibration · full axis travel
Linear/Angularmeasuring straightness · angles · squareness
XL-80 / XM-60Renishaw — Ballbar + Interferometer
Manufacturers: Renishaw XL-80 · Keysight 5530
▶ YouTubeAutocollimator
0.1 arc-secondRemote Angles
Principleparallel beam → Mirror → reflected angle
Accuracy±0.1" arc = ±0.5μrad
Userail straightness · CMM verification · optics
DigitalCCD + LCD — automatic readout
Manufacturers: Taylor Hobson · Brunson
▶ YouTube💎 Hardness Testing
Rockwell Hardness (HRC/HRB/HRA)
ISO 6508Fast · Common
HRC (C scale)Diamond Brale · 150kg · HRC 20-70
HRB (B scale)1/16" ball · 100kg · soft materials
HRADiamond · 60kg · carbide, coatings
HRN15/30/45Superficial — thin material, coatings
Minimum ThicknessHRC: 1.5mm · HRN15: 0.2mm
Fast and automated — the most common in industry!
Manufacturers: Wilson (Buehler) · Mitutoyo · ZwickRoell
▶ YouTubeManufacturers: Wilson (Buehler) · Mitutoyo · ZwickRoell
Vickers Hardness (HV)
ISO 6507High Precision
IndenterDiamond Pyramid 136°
LoadsHV0.001-HV100 (1g to 100kg)
Micro VickersHV0.01-HV1 → coatings, Case layer
Diagonal MeasurementHV = 1.854 × F/d² (d=average of diagonals)
Advantageany hardness, any thickness, precise
▶ YouTubeBrinell Hardness (HBW)
ISO 6506Castings · Steel
IndenterCarbide ball 2.5/5/10mm
Loads187.5-3000 kg · HB 20-650
FormulaHBW = 2F / (πD(D-√(D²-d²)))
Measurementmicroscope indent diameter measurement
▶ YouTubeLeeb / UCI — Portable Hardness
PortableHL → HRC/HB/HV
Leeb ReboundHL = 1000 × v_return/v_impact
UCI (Ultrasonic)frequency shift, Vickers indenter
Accuracy±3-5% vs bench tester
Uselarge parts · in-field · welds
▶ YouTubeShore A/D — Rubber/Plastic Hardness
ISO 868Polymers
Shore Asoft rubber · silicone · 0-100 HA
Shore Dhard plastic · 0-100 HD
IRHDInternational Rubber Hardness Degrees
▶ YouTube🔄 Hardness Conversion Table (ISO 18265 / ASTM E140)
| HRC | HB (3000kg) | HV (10kg) | Steel UTS MPa | Use |
|---|---|---|---|---|
| 20 | 226 | 238 | ~780 | lightly hardened steel |
| 30 | 286 | 302 | ~1010 | moderately hardened |
| 40 | 371 | 392 | ~1280 | well hardened |
| 50 | 481 | 513 | ~1640 | highly hardened |
| 55 | 551 | 596 | ~1870 | cutting tools, D2, M2 |
| 60 | 654 | 746 | ~2100 | tools, bearings |
| 65 | — | 900 | — | HSS, carbide (limited) |
| HB 120 | HB 120 | HV 126 | ~420 | aluminum, annealed steel |
| HB 200 | HB 200 | HV 210 | ~680 | structural steel, SS |
⚠️ Conversions are not exact — ±5-10% · always use ASTM E140 tables for the specific material!
💎 Advanced Topics — Sample Prep and Case Depth
Knoop Hardness
HKElongated Indenter
IndenterRhombic pyramid · 7.11:1 diagonal ratio
Advantage↓depth → ↑micro-regions · ceramics
LoadsHK0.01 to HK1
FormulaHK = 14.229 × F / d²
Useceramics · coatings · dental · thin layers
ASTM E384 · measures only the long diagonal (easier)
▶ YouTubeCase Depth — Hardened Layer Depth
ECD / TCDMetallographic Section
ECD (Effective)down to HV 550 (HRC 52) — Case/Core boundary
TCD (Total)full layer depth down to Core
Methodsection → Mounting → Polishing → HV Profile
TraverseHV readings every 0.1-0.5mm
Case Carburizingtypical ECD: 0.5-1.5mm
Standard: ISO 2639 (Case Hardening) / AMS 2759
▶ YouTubeMetallographic Sample Prep
Cutting → Mounting → Polish
CuttingAbrasive Saw / Wire EDM — no burning!
Mountinghot Bakelite / cold Epoxy
GrindingSiC Paper: P120→P240→P320→P600→P1200
Polishing3μm Diamond → 1μm → OPS 0.04μm
EtchingNital (steel) / Keller (Al) / Marble (SS)
▶ YouTubeNanoindentation
mN · nmThin Coatings
Force0.1-500 mN
Depth10-10,000 nm
Oliver-PharrH and E from the load-displacement curve
UseDLC, PVD/CVD coatings, MEMS
Manufacturers: Bruker Hysitron · Fischer Picodentor
▶ YouTube⚡ NDT — Non-Destructive Testing
VT — Visual Testing
Level I-IIIASNT / EN 473
Direct VTeyes · distance <600mm · >500 lux
Remote VT (RVI)Borescope · Camera · Drone
AidsWeld Gauge · Fillet Gauge · Magnifier
StandardsISO 17637 (welding) · ASTM E1316
Manufacturers: Olympus · GE Inspection
UT — Ultrasonic Testing
Pulse-EchoTOFD · Phased Array
Pulse-Echoecho return from a defect · 1-20 MHz
TOFDTime of Flight Diffraction · ↑accuracy
PAUTPhased Array · sectorial image
EMATno Couplant needed! gas, high temp.
Minimum Thickness0.1mm (UT thickness) · 1mm (defects)
▶ YouTubeRT — Radiographic Testing
Radiation!X-Ray · γ-Ray
X-Ray150-450 kV · steel up to 100mm
γ-Ray Ir-19220-100mm steel · portable
γ-Ray Co-6060-200mm steel · higher energy
Digital DR/CR↑speed · ↓waste · DICONDE
CT Industrial3D image inside the part · Zeiss VoluMax
▶ YouTubeET — Eddy Current Testing
ConductorsCoatings · Cracks
Principleinduced current → impedance change
Frequency100Hz-10MHz · ↑freq=↓penetration
Skin Depth δδ = 503√(ρ/μf) mm
Usescoating thickness · fatigue cracks · sorting
Advantagenon-contact · fast · automation
▶ YouTubeLT — Leak Testing
He · Pressure · Vacuum
Helium Leak10⁻¹⁰ mbar·L/s — the most sensitive!
Pressure Decay↑pressure → measure the drop · cheap
Bubble TestMIL-STD-202 Method 112
Vacuum Boxchecking welds with soap solution
▶ YouTubeThermography
IR CameraNon-Contact
Passive IRTnatural heat → finding defects/leaks
Active IRTexternal heat source → Lock-in/Flash
Thermal Resolution<0.02°C (NETD)
ApplicationsCFRP delamination · electronics · construction
▶ YouTube| Method | Abbrev. | Detects | Materials | Minimum Defect | Standard |
|---|---|---|---|---|---|
| Visual Testing | VT | surface defects | any | 0.5mm | ISO 17637 |
| Liquid Penetrant | PT | surface cracks | non-porous | 0.1mm | ASTM E165 |
| Magnetic Particle | MT | surface + near-surface | ferromagnetic only | 0.1mm | ASTM E709 |
| Ultrasonic | UT | inside the part | solids | 0.5mm (PAUT: 0.2mm) | ISO 17640 |
| Radiography | RT | internal + volumetric | any | 2% thickness | ISO 17636 |
| Eddy Current | ET | surface · coating | conductors | 0.2mm | ISO 15549 |
| Helium Leak | LT | micro-leaks | sealed assemblies | 10⁻¹⁰ mbar·L/s | ISO 20485 |
⚡ NDT — Certification and Advanced Methods
ASNT / EN ISO 9712 — Certification Levels
Level I · II · IIISNT-TC-1A
Level Itesting under supervision · execution only
Level IIindependent · interpretation · reports · certifying others
Level IIImethods · training · specifications · discipline owner
ASNT SNT-TC-1AUS — company-based (Internal Certification)
EN ISO 9712Europe/Israel — external certification!
NAS 410aerospace — stricter than SNT
Israeli defense industry: EN ISO 9712 preferred
PAUT — Phased Array UT
Sectorial ScanS-Scan / E-Scan
Principle16-128 elements → beam steering
S-Scan (Sectorial)angle sweep 40-70° → fan-shaped image
E-Scan (Linear)electronic linear scan
TOFDTime of Flight Diffraction + PAUT = best combination
Reference BlockSDH / FBH / Notch — sensitivity calibration
Certified substitute for RT on welds! · ASME VIII Div.1
Manufacturers: Olympus OmniScan · Eddyfi M2M
▶ YouTubeManufacturers: Olympus OmniScan · Eddyfi M2M
AUT — Automated Ultrasonic
↑ConsistencyZONE Discrimination
Useoil/gas piping · ship welding · spokes
Zone Methoddividing thickness into zones · focus per zone
Speed200-600mm/sec · vs. Manual 50mm
TOFD+PAUTtwo techniques combined = full coverage
Manufacturers: Zetec · Applus RTD
▶ YouTubePOD — Probability of Detection
a90/95Aerospace Requirement
PODprobability of detecting a defect of a given size
a90/95defect size → POD 90% at 95% confidence
Hit/Miss60-90 defects for statistical analysis
MIL-HDBK-1823AUSAF guide for POD
Retire Limit = a90/95 divided by Safety Factor
Required before deploying a new NDT method in aerospace!
Required before deploying a new NDT method in aerospace!
MFL — Magnetic Flux Leakage
Piping · TanksOnline
Principlestrong magnetic field → flux leaks at a defect
Useunderground oil/gas piping · storage tanks
ILI PigIn-Line Inspection — while flowing!
Minimum Corrosion5-10% wall thickness
Manufacturers: T.D. Williamson · ROSEN
▶ YouTubeAE — Acoustic Emission
Passive↑Real-Time Active
Principlecrack growth → acoustic wave → sensor
Advantagecontinuous monitoring under load!
Source LocationTriangulation from 4+ sensors
Usepressure testing · CFRP tanks · bearings
▶ YouTube📊 SPC — Statistical Process Control
Cp / Cpk — Process Capability
Cpk≥1.33Cpk<1.0 problem
CpCp = (USL-LSL) / 6σ
CpkCpk = min[(USL-μ)/3σ, (μ-LSL)/3σ]
Cpk ≥ 1.67aerospace/medical — 5 sigma
Cpk ≥ 1.33general industry — 4 sigma
Cpk ≥ 1.00minimum acceptable (limited)
Pp / Ppklike Cp/Cpk but σ=all data
Cp = potential · Cpk = actual performance (includes shift)
▶ YouTubeControl Charts
X̄-R · X̄-S · p · c · u
X̄-R Chartmean+range · n=2-10
X̄-S Chartmean+standard deviation · n>10
X-MR (ImR)individual value+moving range · n=1
p Chartdefect rate (Attribute)
c / u Chartnumber of defects / defects per unit
UCL/LCLX̄ ± 3σ (99.73% in control)
Western Electric Rules: 8 rules for detecting anomalies
▶ YouTubeWestern Electric Rules — 8 Rules
Special Cause
Rule 1a point outside 3σ (UCL/LCL)
Rule 29 consecutive points on the same side of CL
Rule 36 consecutive points trending up/down
Rule 414 points alternating up/down
Rule 52 of 3 outside 2σ (same side)
Rule 64 of 5 outside 1σ (same side)
Rule 715 consecutive points within ±1σ (both sides)
Rule 88 consecutive points outside ±1σ (both sides)
Any rule triggered = suspected special cause → investigate immediately!
Six Sigma
DMAIC3.4 PPM
Defineproblem definition · CTQ · Project Charter
Measuremeasurement · Baseline · MSA · Gage R&R
AnalyzeRoot Cause · Fishbone · Pareto · DOE
Improvesolution · Pilot · Validation
ControlControl Plan · SPC · sustaining improvement
6σ Performance3.4 PPM · Cpk = 2.0
DPMO = Defects Per Million Opportunities
▶ YouTube| Sigma Level | Cpk | DPMO | % Good | Interpretation |
|---|---|---|---|---|
| 1σ | 0.33 | 691,462 | 30.9% | chaos |
| 2σ | 0.67 | 308,538 | 69.1% | poor |
| 3σ | 1.00 | 66,807 | 93.3% | minimum |
| 4σ | 1.33 | 6,210 | 99.38% | good industrial |
| 5σ | 1.67 | 233 | 99.977% | aerospace/medical |
| 6σ | 2.00 | 3.4 | 99.9997% | Six Sigma Goal |
📊 Additional Statistical Tools
Normality Test
Anderson-DarlingShapiro-Wilk
Anderson-Darlingp>0.05 → normal (fail to reject H0)
Shapiro-Wilkn<50 — preferred for small samples
Histogramvisual check — bell shape
Normal Probability Plotpoints on a straight line → normal
If not normalBox-Cox Transform · Weibull · Non-param
Fishbone / Ishikawa Diagram
Root Cause6M
Machineequipment · maintenance · calibration
Methodmethod · process · work instructions
Materialmaterial · supplier · lot
Manpeople · training · errors
Measurementmeasurement · Gage R&R
Mother Natureenvironment · temp. · humidity
▶ YouTubePareto Analysis — 80/20
80% Problems = 20% Causes
Principlesort by frequency/cost/severity
Chartbars + 80% cumulative line
Useprioritizing corrective actions · ↓maximum damage
Pareto of Pareto2 levels — primary + secondary cause
Always ask: "which 20% of causes drive 80% of the defects?"
▶ YouTubeDOE — Design of Experiments
Full/Fractional Factorial
Full Factorial2ᵏ — all factor combinations
Fractional2ᵏ⁻ᵖ — fewer runs
TaguchiL9/L18 — Robust Design
Response Surfaceoptimization — Central Composite
Main EffectsInteraction Plots + ANOVA
▶ YouTubeHypothesis Testing
p-valueH0 / H1
t-Test (means)before/after improvement · 2 groups
F-Test / ANOVA3+ means · multiple factors
Chi-SquareAttribute data · Contingency Table
α = 0.055% significance level — common
p < αreject H0 — ↑significant difference!
"p<0.05 → significant" = the difference is not due to chance
DPMO · Yield · RTY
First Pass YieldRolled Throughput
DPMODefects Per Million Opportunities
FPYFirst Pass Yield = good first time/total
RTYRTY = FPY₁ × FPY₂ × ... × FPYₙ
RTY Example0.95×0.97×0.98 = 90.3% — surprising!
RTY reveals hidden problems that FPY masks via Rework
📐 Gage R&R — MSA / Measurement System Analysis
Gage R&R — What Is It?
AIAG MSA 4th%GR&R <10%
Repeatabilitysame measurement × same instrument × same operator
Reproducibilitysame part × same instrument × different operators
GR&R√(EV² + AV²)
%GR&R <10%✅ acceptable
%GR&R 10-30%⚠️ improvement recommended
%GR&R >30%❌ not acceptable!
▶ YouTubeR&R Study Design
10 Parts × 3 Operators × 2 Trials
Minimum Parts10 (representative of the process)
Operators2-3 (everyone who actually measures)
Trials2-3 (random, blind)
NDCNumber of Distinct Categories ≥5
MethodsANOVA / Average & Range Method
Bias · Linearity · Stability
Full MSA
Biasdifference between measured and true value
LinearityBias change across the measurement range
StabilityBias change over time (drift)
Resolution≤ 10% of tolerance — mandatory!
Rule: Resolution ≤ 1/10 × Tolerance
Example: Tol=0.1mm → resolution ≤0.01mm
Example: Tol=0.1mm → resolution ≤0.01mm
📐 Extended MSA — Type 1 Study and Attribute Agreement
Type 1 Study — Initial Tool Capability
Cg / CgkBefore R&R
What it is50 repeated measurements × 1 operator × 1 part
CgCg = 0.2 × T / (6 × σ_g)
Cgklike Cg but includes bias from true value
CriterionCg ≥ 1.33 AND Cgk ≥ 1.33
Whenbefore Gage R&R · new tool · repair
Type 1 = testing the tool itself! R&R = tool + operator
Attribute Agreement Analysis — AAA
Pass / FailVisual Inspection
Usevisual inspections · Go/NoGo · Welding VT
Structure20-30 parts × 3 operators × 2 trials
Kappaκ ≥ 0.75 = acceptable
Effectiveness% agreement with Reference Standard
False Acceptworse than False Reject!
AIAG MSA 4th ed. · cost of False Accept >> False Reject
▶ YouTubeR&R Calculator — ANOVA Analysis
Variance Components
σ²_totalσ²_parts + σ²_repeatability + σ²_reproducibility
%EV%EV = 100 × σ_repeatability / σ_total
%AV%AV = 100 × σ_reproducibility / σ_total
%GR&R√(EV² + AV²) / (k × σ_total)
kk=5.15 (99% conf) · k=6 (±3σ)
ANOVA = more accurate than Average&Range Method
Detects Interaction between operator and part!
Detects Interaction between operator and part!
Resolution & Discrimination
Rule of 1:10NDC ≥ 5
Golden RuleResolution ≤ Tolerance / 10
NDCndc = 1.41 × (σ_parts / σ_grr)
NDC ≥ 5tool can distinguish ≥5 categories
NDC = 1the tool "can't see" variation between parts!
Example: Tol=0.1mm · tool Resolution=0.001mm ✅
tool Resolution=0.02mm → only 5 categories ⚠️
tool Resolution=0.02mm → only 5 categories ⚠️
Bias Study — Systematic Bias
Reference PartTraceable
BiasX̄_measured - Reference_Value
CriterionBias % = |Bias| / T × 100 ≤ 5%
t-Testis the Bias significant? (p<0.05)
Bias Causeswrong calibration · wrong Datum · temp.
The Reference part must be calibrated! ISO 17025 Traceability
Linearity Study
Full RangeBias vs. Size
What it isBias change across the measurement range
Structure5 reference parts × 12 measurements each
Linearity %Slope × Process Variation / T × 100
CriterionLinearity % ≤ 5%
Causesworn Anvil · worn spring · electronics
Old micrometer: ↑large linearity = insufficient calibration!
🎯 AQL & Acceptance Sampling Plans
AQL — Acceptable Quality Level
ISO 2859-1MIL-STD-1916
AQL 0.065defense/aerospace — critical
AQL 0.25medical/critical — minimum
AQL 1.0most common — general industry
AQL 4.0mass production — lower quality
Inspection LevelsI=reduced · II=normal · III=tightened
▶ YouTubeLetter Code + Sample Size
ISO 2859-1 Table
N 2-8 → Code An=2
N 9-15 → Code Bn=3
N 51-90 → Code En=13
N 281-500 → Code Hn=50
N 1201-3200 → Code Kn=125
N >500,000 → Code Rn=2000
Switching Rules
Normal → Tightened → Reduced
Normal → Tightened2 of 5 lots rejected
Tightened → Normal5 consecutive lots passed
Normal → Reduced10 consecutive lots passed
Reduced → Normalrejection / out-of-bounds score
Tightened = larger n ← ↑inspection cost!
🧮 Quick AQL Calculator
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🎯 Advanced Sampling Methods
Variables Sampling — ISO 3951
Quantitative vs. AttributeSmaller n!
Principlequantitative measurement → smaller n than Attribute
ExampleAQL 1.0 N=500: Attribute n=50 · Variables n=18!
StandardISO 3951-1/2/3 / MIL-STD-414
Conditionσ known (Z formula) or unknown (S formula)
Limitationnormality is mandatory!
↓significant inspection cost for measurable parameters
Zero Acceptance (c=0) — ANSI/ASQ Z1.4
c=0↑↑Consumer Protection
Principle0 defects acceptable — reject on the first one!
n for c=0larger than standard AQL
Advantage↑protection · simple · no Tightened switching
Usemedical · defense · life-safety risk
Standard ISO 2859-1: c=1 · Zero Acceptance: c=0 (stricter)
Skip-Lot Sampling
↓Inspection CostApproved Supplier
ANSI/ASQ S1inspect 1 of k lots
Entry4 consecutive defect-free lots
k=2inspect 50% of lots
Cancellation1 defect → return to standard inspection
Requires: approved AVL + clean history + ISO 9001
OC Curve — Plan Performance Curve
Producer/Consumer Risk
OC CurveP(accept) vs. lot defect rate
α (Producer's Risk)P(reject AQL lot) = 0.05 (5%)
β (Consumer's Risk)P(accept LTPD lot) = 0.10 (10%)
LTPDLot Tolerance Percent Defective
↑n → sharper OC Curve → ↑protection · ↑cost
Always: ↑n = ↓β (consumer's risk)
Always: ↑n = ↓β (consumer's risk)
⚖️ Calibration & Traceability
ISO/IEC 17025 — Laboratory Calibration
AccreditationILAC
Purposecompetence of calibration/testing labs
Traceabilitychain to SI (BIPM/NIST/NMI)
IsraelISRAC — the accreditation authority
Calibration Certificatemust include: U, k, conditions, date
Uncertainty UU = k × uc (k=2 = 95% confidence)
Labs: Israel Standards Institute NMLI · NIST
Calibration Intervals
3-12 Months
Micrometer12 months (moderate use)
Vernier6-12 months
Dial Indicator6 months
CMM6-12 months + full ISO 10360
Gauge Blocks12-24 months
Torque Wrench12 months / 5000 uses
ISO 9001: interval based on history and usage load!
Calibration Management
Tags · System
Calibration Tagtool number · date · next due date
Not Fit For UseOut of Cal → ↑immediate isolation!
Software ManagementAsset management · Reminder · History
Storage Conditions20°C ±2°C · 40-60% RH · no vibration
Software: QSO Calibration · Fluke MET/CAL
⚖️ Measurement Uncertainty
GUM — Guide to Uncertainty
ISO/IEC Guide 98-3BIPM
GUMGuide to Uncertainty in Measurement
Type Astatistical — repeated measurements (σ/√n)
Type Bother information — certificate · spec · literature
uc (Combined)uc = √(uA² + uB1² + uB2² + ...)
U (Expanded)U = k × uc · k=2 → 95% coverage
Result: x = X ± U [units], k=2, 95%
Example: 25.003 ± 0.004 mm, k=2
Example: 25.003 ± 0.004 mm, k=2
Uncertainty Budget
Contributions
u_calibrationfrom the calibration certificate (Type B)
u_repeatabilityType A — √(σ²/n)
u_resolution±0.5 × resolution / √3
u_temperatureCTE × ΔT × L / √3
u_cosineCosine Error = L(1-cosθ)
Excel budget sheet: each contribution → uc → U
Requirement: U ≤ T/4 (Quarter Rule)
Requirement: U ≤ T/4 (Quarter Rule)
Calibration Hierarchy
SI → NMI → Reference → Working
SI (International)BIPM Paris — world reference
NMI (National)NIST/NPL/PTB/NMLI Israel
Accredited LabISO 17025 · ILAC mutual recognition
Reference Stdinternal lab — Gauge Blocks Grade 0
Working Stdshop-floor tools — Grade 1/2
Every level adds uncertainty — the Traceability chain!
▶ YouTubeTUR — Test Uncertainty Ratio
TUR ≥ 4:1Quarter Rule
TURTUR = Tolerance / (2 × U_calibration)
TUR ≥ 4:1✅ acceptable for most industries
TUR ≥ 10:1defense/aerospace
TUR < 4:1⚠️ consider Guard Banding
Guard Banding = narrowing the test tolerance by U
ANSI/NCSL Z540.3: minimum TUR 4:1
ANSI/NCSL Z540.3: minimum TUR 4:1
📦 Incoming Quality Control
IQC — Incoming Quality Control
Inspection PlanCOC · Report
Step 1: DocumentationCOC · Mill Cert · PO · Spec
Step 2: Identificationmaterial · grade · Heat Number
Step 3: Measurementcritical dimensions · AQL sampling
Step 4: Propertieshardness · RM/Rp0 (if required)
Step 5: DecisionAccept / Reject / MRB
MRB = Material Review Board — non-conforming
PPAP — Automotive Industry
AIAG 4th EditionLevel 1-5
Level 1Part Submission Warrant only
Level 2PSW + samples + limited documentation
Level 3PSW + samples + full documentation (most common)
Level 4as defined by the customer
Level 5everything + supplier site visit
18 elements including: DFMEA, Control Plan, MSA, Cpk
▶ YouTubeMill Certificate
EN 10204Type 2.1-3.2
Type 2.1declaration of conformity — not specific
Type 2.2non-specific tests per procedure
Type 3.1specific tests + manufacturer's own approval
Type 3.23.1 + independent customer approval
Aerospace/medical = 3.1 minimum! · NADCAP = 3.2
Check: Heat No. · Chemical · Mechanical · UTS/Rp0
Check: Heat No. · Chemical · Mechanical · UTS/Rp0
Non-Conformance
NCRMRB · CAR
NCRNon-Conformance Report — documentation
DispositionUse-As-Is / Rework / Scrap / Return
CARCorrective Action Request — to the supplier
8D8 Disciplines → Root Cause + Fix
SCARSupplier CAR — 30 days to respond
Use-As-Is → requires engineering + customer approval!
📦 Supplier Management and Non-Conformances
ASL / AVL — Approved Supplier List
Approved Supplier List
ASLApproved Supplier List — approved suppliers
AVLApproved Vendor List — material suppliers
Entry to ASLaudit · first-article sampling · FAI
Supplier ScoringOTD% · PPM · SCAR Rate · Audit
Removal3 SCAR ← Hold → removal from AVL
AS9100/IATF: AVL documentation + annual update mandatory
Dock-to-Stock — DTS
No IQC InspectionTop Suppliers
Entry to DTS12+ clean lots · Cpk≥1.67 · ISO 17025
Methodlabel scan · COC ← straight to warehouse
Periodic Check1/20 lots — Random Audit
DTS Revocationany finding → immediate return to IQC
↓IQC cost 70-80% · ↓Lead Time · ↑supplier trust
COC — Certificate of Conformance
Conformity CheckAerospace Mandatory
What to CheckP/N · Revision · Quantity · Heat/Lot No.
Speccitation of specific standards (AMS/MIL/EN)
SignatureQuality Manager · date · stamp
CounterfeitSAE AS5553 — counterfeit parts
⚠️ A falsified COC is a criminal offense in aerospace!
Check: CAGE Code · DUNS · AS9120 accreditation
Check: CAGE Code · DUNS · AS9120 accreditation
SCAR — Supplier Corrective Action
8D Response30 Days
D1-D3team + problem + Containment → 24h
D4-D5Root Cause + permanent fix → 14 days
D6-D7effectiveness verification + recurrence prevention → 30 days
D8team recognition + closure
Effectivenessmeasured: 0 recurrence in 90 days
Document evidence for every D! AS9100 requires evidence
Supplier Rating
A/B/C/DSupplier KPI
OTDOn-Time Delivery % · weight 30%
Quality PPMParts Per Million defective · weight 40%
SCAR Responsespeed + quality of response · weight 20%
Audit Scoreaudit findings · weight 10%
A ≥ 90Preferred · B=80-90 · C=70-80 · D<70
D = Development Program → 90 days to improve or be replaced
🏆 Quality Management Standards
ISO 9001:2015 — The Foundation
7 PrinciplesCross-Industry
Context4: organizational context · risk management
Leadership5: policy · management responsibility
Planning6: risks · quality objectives
Operation8: production · process control
Evaluation9: measurement · internal audit
Improvement10: non-conformities · Corrective Action
AS9100 Rev D — Aerospace
IAQG9001 + Additions
BasisISO 9001 + aerospace requirements
Key Add-onsConfiguration Management, FAI, AS9102
RiskProduct & Process Risk Management
First ArticleFAI mandatory for every change!
OASIS DBdatabase of supplier certifications
IATF 16949 — Automotive Industry
IATF9001 + Core Tools
Core ToolsAPQP · PPAP · FMEA · MSA · SPC
APQPAdvanced Product Quality Planning
Control Planfull production control plan
Customer Specificadditional VW / Ford / GM / Toyota requirements
Certification Bodies: TÜV · Bureau Veritas
NADCAP — Special Processes
PRIAerospace
Special Processeswelding · NDT · coatings · heat treatment
AC7004Welding Audit Checklist
AC7114NDT Audit Checklist
AC7108Heat Treatment
Merit Status12/18 months for top-performing companies
Required for Boeing/Airbus/Lockheed/Rafael!
Management: PRI (Performance Review Institute)
Management: PRI (Performance Review Institute)
ISO 13485 — Medical Devices
MDR 2017/745FDA 21 CFR 820
Design ControlDHF, DMR, DHR — full documentation
Risk ManagementISO 14971 — medical devices
SterilityISO 11135 / 11137 (sterilization)
TraceabilityUDI — unique device identifier
Certification Bodies: TÜV Rheinland · BSI
8D — Problem Solving
8 StepsRoot Cause
D1form the team
D2define the problem (Is / Is Not)
D3immediate Containment Action
D4Root Cause Analysis (5 Why, Ishikawa)
D5-D6permanent solution + verification
D7-D8recurrence prevention + team recognition
▶ YouTube🏆 Core Quality Tools — APQP · FMEA · Control Plan
APQP — Advanced Product Quality Planning
5 PhasesAutomotive
Phase 1Plan & Define — VOC · CTQ · Targets
Phase 2Product Design — DFMEA · DVP&R
Phase 3Process Design — PFMEA · Control Plan
Phase 4Product Validation — PPAP · Cpk
Phase 5Feedback · Corrective Action · Launch
AIAG APQP Manual 2nd Edition
FMEA — Failure Mode & Effects Analysis
DFMEA · PFMEARPN · AP
DFMEADesign FMEA — design flaws
PFMEAProcess FMEA — manufacturing flaws
RPN (Old)Severity × Occurrence × Detection
AP (AIAG 2019)Action Priority H/M/L — replaces RPN
Severity 9-10action required even at low probability!
Control Plan
3 VersionsPrototype/Pre/Production
HeaderP/N · Rev · Customer · PFMEA Link
Main ColumnsCharacteristic · Spec · Method · Size · Freq
Control MethodSPC · Attribute Check · Go/NoGo · Visual
Reaction Planwhat to do on deviation · Containment
Special Char.◆ KPC (Key Product) · ★ KCC (Key Control)
Control Plan = "production constitution" — mandatory update for any change
5 Why
Toyota MethodRoot Cause
Why 1why did the problem occur?
Why 2why did Why 1 happen?
Why 3-5continue until the real root cause
Root Causethe Why you can't continue past = Root Cause
Ruleask "why" not "who" — ↓blame
5 Why + Fishbone = the strongest combination for Root Cause!
▶ YouTubeRisk Management
ISO 31000ISO 14971 (Medical)
Risk = S × PSeverity × Probability
Risk Matrix3×3 or 5×5 · High/Med/Low
ALARPAs Low As Reasonably Practicable
Residual Riskafter mitigation — must be documented
Risk Registerlive updates + Owner + Due Date
ISO 9001:2015 = Risk-Based Thinking is mandatory!
Audit — Quality Audit
1st/2nd/3rd PartyISO 19011
1st Partyinternal audit — Internal Audit
2nd Partycustomer audits supplier — Supplier Audit
3rd Partyexternal body — ISO/AS9100 certification
Finding TypesMajor / Minor / Observation / OFI
Major→ 30-day CAR · ↓certification risk
ISO 19011 = guide for management system audits
▶ YouTube🧮 Quality Calculators
Cpk Calculator — Process Capability
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Quick Gage R&R Calculator
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🧮 Additional Calculators
TUR Calculator — Test Uncertainty Ratio
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DPMO & Sigma Level Calculator
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Sine Bar Calculator — Precise Angle
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