Integrated Process Capability Analysis Model (IPCAM) for a Product with Multiple Quality Characteristics 報告人 : 游崑慈
1.Supply chain management 2.Process capability indices 3.Taguchi loss function 4.Process yield & Six-sigma 5.IPCAM 6.Future applications Outlines
Supply chain management Manufacturing Distribution Supplier INFORMATION FLOW Retail OutletConsumer CASH FLOW Transfer
LSL USL Process distribution m d LSL USL Process distribution m d 製造業通常透過統計製程管制 (SPC) 來監控與改善產品品質,使製程變異降 低進而達到穩定狀態,當製程穩定後,品管工程師想進一步了解產品符合規 格的能力,或出現不良品的比率有多少?
Nominal-the-best Process Capability Index 製程能力指標 (PCI) 便是用來衡量製程符合規格的能力,與結合製 程參數與製程規格 (LSL , T , USL) 的函數,能夠表示製程中心偏移 與製程變異程度,因此常被用來評估供應商是否有能力製作出符合 產品規格的一種量數,並作為購買契約上買賣雙方對品質要求的依 據以及工廠內部持續改善品質的參考。 LSL USL Process distribution m d T Yield% 2Φ(3C pm ) - 1
Taguchi loss function LSL USL T U.S.A Japan Loss function
Smaller-the-better Process Capability Index C pu = Quality characteristics : roughness, noise, waiting time, thickness. Yield% = (3 C pu ) 2 (3 C pu ) - 1 μBμB
Larger -the-better Process Capability Index C pl = Quality characteristics : Life-span 、 hardness 、 pulling force 、 resolution. Yield% = (3C pl ) 2 (3C pl ) – 1
Process Yield %Yield = 2Φ(3C pu ) – 1 %Yield = 2Φ(3C pl ) – 1 %Yield 2Φ(3C pm ) - 1 PCI ↗ process yield ↗ process loss ↘
假設品質特性符合 Normal distribution T=100U=112L=88 若 則稱此製程具有 6-sigma quality level 。 Six Sigma
Six-sigma process concept Normal distribution centered Spec. Limit Percent Defective PPM % 8
Integrated Process Capability Analysis Model (IPCAM)
Estimations One -side capability indices (UMVUE) i {u, l } is distributed as, where
C pl : represent axes X (larger-the-better) C pu : represent axes Y (smaller-the-better) C pm : represent XY plane (nominal-the-best)
Two-side capability index Estimations It is a more complicated distribution, we often used the mathematical software to do numerical Analysis.
Hypothesis test for one-side quality specification where i {u, l}. The critical regions are C S = { | S 0 } and the critical value S 0 is determined by Pr ( s 0 | C pi ) = H 0 : C pi H 1 : C pi .
Hypothesis test for two-side quality specification H 0 : C pm H 1 : C pm Pr ( m 0 | C pm ) =
IPCAM (sampling inspection)
Item LSLTUSL S 0 m 0 A B C D E F G H I
S 0 =1.899 m 0 =1.911
Future Applications Technical education quality management model Medical service quality control Human resources management