C13 LTMS discussion Follow-up to San Antonio O&H meeting Elisa Santos November 29 th, 2005

2 Objective Reevaluate the decision made during the O&H meeting –The group decided to use targets and standard deviations based on 29 tests (matrix plus concurrent tests) without taking into account that Lab F is different from all the other labs in Delta OC and that Lab B is different from the other labs in TLC The immediate consequence of using inflated standard deviations is that all stands will calibrate Also, the control chart bounds generated for the chosen reference oil will be affected by this decision, making it harder to detect Lab shifts

3 Data source 29 tests from the ltms file –23 matrix tests for PC10 oils –3 tests for PC10 G –3 concurrent tests Critical parameters: –Delta OC –TGC –TLC –R2TCA (not included)

4 Delta OC Including Lab F Transformation: square root Oil discrimination Lab F is different from all Labs Final model: Lab & Oil Type RMSE = 0.57 Excluding Lab F Transformation: square root Oil discrimination Labs are similar Final model: Lab & Oil Type RMSE = 0.59

5 square root of Delta OC

6 Means, Standard Deviations, LSMEANS & Oil discrimination Before and After removing Lab F Before After RMSE = 0.57 RMSE = 0.59

7 Options for Delta OC Summary for potential reference oils –PC10 B: Original RMSE: 0.57 Original STDEV: 0.73; Eliminating Lab F: 0.32 –PC10 E: Original RMSE: 0.57 Original STDEV: 1.43; Eliminating Lab F: 0.76 The other oils have only three or two tests associated to them Option1: Use LSMEANS and Unique RMSE for Delta (using data from all labs) Option2: Use Means and Standard deviations after removing Lab F from the calculations Option 3: Use Means and Standard deviations (using data from all labs)

8 Outlier screened TGC No Oil discrimination Lab G different from Lab A Cylinder Effect Final model: Lab & Oil RMSE = 6.47 LSMEANS for Oil LSMEANS for Lab

9 OTGC RMSE = 6.47 Lab G different from Lab A

10 Options for OTGC Option1: Use LSMEANS and Unique RMSE for OTGC (using data from all labs) Option 3: Use Means and Standard deviations (using data from all labs)

11 scrnd TLC PC10 F is different from all oils except for PC10 C & PC10 G Lab B different from Lab A and Lab G. The severity of Lab B is more clear with the Tech & Base Oil analysis. Final model: Lab & Oil Type RMSE= 4.69 LSMEANS for Oil LSMEANS for Lab

12 scrnd TLC RMSE = 4.69

13 Means and Standard Deviations before and after removing Lab B RMSE = 4.5 RMSE = 4.69 Before After

14 Options for scrnd TLC Option1: Use LSMEANS and Unique RMSE for scrnd TLC (using data from all labs) Option2: Use Means and Standard deviations after removing Lab B from the calculations Option 3: Use Means and Standard deviations (using data from all labs)

15 Impact on calibration Options considered for the three parameters: –Shewhart calibration 111 (Option 1 for Delta/ Option 1 for OTGC/ Option 1 for scrnd TLC) –Shewhart calibration 212 (Option 2 for Delta/ Option 1 for OTGC/ Option 2 for scrnd TLC) –Shewhart calibration 333 (Option 3 for Delta/ Option 3 for OTGC/ Option 3 for scrnd TLC) –… there are other combinations, but these are the ones I generated Look at EXCEL spreadsheet..\Excel files\Discussion about Targets and precision.xls –Shewhart calculations by parameter –EWMA for severity adjustments (?)

16 Summary of Impact on Lab/ Stand calibration Row Color represents oil type A Shewhart Cal row different from zero indicates that that particular Yi is falling out of the K bounds for at least one parameter