6SIGMA术语列表解释6[教学]

HYPOTHESIS TESTS, NULL: the hypothesis tested in tests of significance is that there is no difference (null) between the population of the sample and specified population (or between the populations associated with each sample). The null hypothesis can never be proved true. It can, however, be shown, with specified risks of error, to be untrue; that is, a difference can be shown to exist between the populations. If it is not disproved, one may surmise that it is true. (It may be that there is insufficient power to prove the existence of a difference rather than that there is no difference; that is, the sample size may be too small. By specifying the minimum difference that one wants to detect and P, the risk of failing to detect a difference of this size, the actual sample size required, however, can be determined.)

IN-CONTROL PROCESS: a process in which the statistical measure being evaluated is in a state of statistical control (i.e., the variations among the observed sampling results can be attributed to a constant system of chance causes). (See also "out-of-control process.")

INNER ARRAY: a Taguchi term used in parameter design to identify the combinations of controllable factors to be studied in a designed experiment. Also called “design array” or “design matrix”.

INSPECTION: measuring, examining, testing, or gauging one or more characteristics of a product or service and comparing the results with specified requirements to determine whether conformity is achieved for each characteristic

INTERACTION PLOT: a graphical display showing how two factors (input variables) interact if one factor’s effect on the response is dependent upon the level of the other factor.

JUST-IN-TIME (JIT): a strategy that coordinates scheduling, inventory, and production to move away from batch mode of production in order to improve quality and reduce inventories.

KAIZEN: a Japanese term that means gradual unending improvement by doing little things better and setting and achieving increasingly higher standards. Masaaki Imai made the term famous in his book Kaizen: The Key to Japan's Competitive Success.

KURTOSIS: a measure of the shape of a distribution. A positive value indicates that the distribution has longer tails than the normal distribution (platykurtosis); while a negative value indicates that the distribution has shorter tails (leptokurtosis). For the normal distribution, the kurtosis is 0.

LCL: lower control limit. For control charts, the limit above which the process subgroup statistics must remain when the process is in control. LCL is typically three standard deviations below the centerline.

LOSS FUNCTION: a technique for quantifying loss due to production deviations from target values.

MAIN EFFECTS PLOT: a graphic display showing the influence a single factor has on the response when it is changed from one level to another. Often used to represent the “linear effect” associated with a factor.

MEAN: the average of a set of values. We usually use x to denote a sample mean, whereby we use the Greek letter m to denote a population mean.