6Sigma定义衡量阶段之过程能力.ppt

Process Capability Johnson Controls, Inc. 3-27-2001 * Stable process No Defective rate - .03195 or 3.2% Process Capability Johnson Controls, Inc. 3-27-2001 * 302 / 9453 = .03195 then go to body of table Process Capability Johnson Controls, Inc. 3-27-2001 * Percent defective and defects - long term data proportion defective means body of table Process Capability Johnson Controls, Inc. 3-27-2001 * Poisson - multiple defects Process Capability Johnson Controls, Inc. 3-27-2001 * Yes - stable Average DPU - .1237 or 12.37% Process Capability Johnson Controls, Inc. 3-27-2001 * 4963 * 6 = 29778 614 / 29778 = .02 Process Capability Johnson Controls, Inc. 3-27-2001 * Go to body of Z table Process Capability Johnson Controls, Inc. 3-27-2001 * Long term - needs to take in all the conditions and changes under normal controls By nature of attribute data - large sample size over time - consider attribute data long term Process Capability Johnson Controls, Inc. 3-27-2001 * Use excel spread sheet - pass code Jim Quilan Process Capability Johnson Controls, Inc. 3-27-2001 * Demonstrate sigma calculator use excel spread sheet file - defects 520, 4963,6 long term data - estimates short term DPMO is first choice Cpk - normal data Ppk - weibull Process Capability Johnson Controls, Inc. 3-27-2001 * Process Capability Johnson Controls, Inc. 3-27-2001 * Process Capability Johnson Controls, Inc. 3-27-2001 * This is OK as long as the Spec limits stay the same Process Capability Johnson Controls, Inc. 3-27-2001 * Sigma Level is number of Std Dev that can fit between specs Sigma Level - number of Std Dev from the center to the specs 6 Sigma - is CpK of 2.0 Process Capability Johnson Controls, Inc. 3-27-2001 * No set length of time - does it capture all the variation Long Term - more variation opportunities captured over longer time periods Black Belt must use process knowledge to know if captured all / most of the possible variation possibilities LT ST: after control, 3