【正文】 icsson Quality Management Institute A Two Level Factorial Design ? Run order is a randomised standard order ? Plus signs and minus signs show high and low levels of factor settings (coded units) ? Can use actual settings rather than plus and minus signs (uncoded units) ? Experiment run order 4 means factor A, B and C set at plus, plus, minus ? Oute of experiment noted in response column CREATING A DESIGN STRUCTURE 1 2 3 4 5 6 7 8 Factor C Factor A Factor B Std Order 1 2 3 4 5 6 7 8 Run Order 3 1 7 4 6 5 8 2 Factor A + + + + Factor B + + + + Factor C + + + + Response EN/FAD 109 0015 169。 Ola Johansson, 1999 Ericsson Quality Management Institute Full Factorial Experiment ? All possible binations of factor levels are investigated Advantages ? Excellent understanding of effect of factors on response Disadvantages ? Generally impractical to conduct ? Very expensive ? Alternative “fractional” factorial designs available that give good results at far less cost Run Factors A B C D E F G Response 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 . . . . . . . . 126 127 128 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 . . . . . . . . 2 2 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 . . . . . . . . 2 2 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 . . . . . . . . 2 2 2 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 . . . . . . . . 2 2 2 1 1 1 1 2 2 2 2 1 1 1 1 2 2 2 2 . . . . . . . . 2 2 2 1 1 2 2 1 1 2 2 1 1 2 2 1 1 2 2 . . . . . . . . 1 2 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 . . . . . . . . 2 1 2 EN/FAD 109 0015 169。 Ola Johansson, 1999 Ericsson Quality Management Institute DOE The Benefits ? Far fewer trials than conventional approach ? Identifies those process parameters that affect output quality ? Reduce process / product variability ? Enables output quality average to be closer to target ? Minimise the effects of ?noise? ? Enable products to be developed that seldom fail ? Reduce product development lead time ? Reducing time and cost to mission new plant and equipment EN/FAD 109 0015 169。 Ola Johansson, 1999 Ericsson Quality Management Institute Creating amp。 effect’ plexity using DoE Reduce variability and target process further using SPC and SIC 。 Time (10, 30 sec)。 quality criteria Manageable evaluation and optimisation …integrating team experience and knowledge with benefits of applied statistical techniques Planning for Success the design environment EN/FAD 109 0015 169。 Ola Johansson, 1999 Ericsson Quality Management Institute DOE The basics A Basic Model A body of explanatory data Measurement of Response (Potential Causes) (Effect) x1 x2 x3 y __ __ __ __ __ __ __ __ __ __ __ __ x y Independent Variable Y = a + bx parameters coefficients a b Dependent Variable A Straight Line A Statistical Model y = ?0 + ?1X1 + ?2X2 + ?3X1X2 + Error ? Linear 2 factor model ? N