Search results
Results From The WOW.Com Content Network
Process capability index. The process capability index, or process capability ratio, is a statistical measure of process capability: the ability of an engineering process to produce an output within specification limits. [1] The concept of process capability only holds meaning for processes that are in a state of statistical control.
Defects per million opportunities. In process improvement efforts, defects per million opportunities or DPMO (or nonconformities per million opportunities (NPMO)) is a measure of process performance. It is defined as. A defect can be defined as a nonconformance of a quality characteristic (e.g. strength, width, response time) to its specification.
Processes that operate with "six sigma quality" over the short term are assumed to produce long-term defect levels below 3.4 defects per million opportunities (DPMO). The 3.4 dpmo is based on a "shift" of ± 1.5 sigma explained by Mikel Harry. This figure is based on the tolerance in the height of a stack of discs. [9] [10]
Design for Six Sigma (DFSS) is a collection of best-practices for the development of new products and processes. It is sometimes deployed as an engineering design process or business process management method. DFSS originated at General Electric to build on the success they had with traditional Six Sigma; but instead of process improvement ...
The table shown on the right can be used in a two-sample t-test to estimate the sample sizes of an experimental group and a control group that are of equal size, that is, the total number of individuals in the trial is twice that of the number given, and the desired significance level is 0.05. [4] The parameters used are:
To calculate first time yield (FTY) you would: Calculate the yield (number out of step/number into step) of each step. Multiply these together. For example: (# units leaving the process as good parts) / (# units put into the process) = FTY. 100 units enter A and 90 leave as good parts. The FTY for process A is 90/100 = 0.9000.
To locate the critical F value in the F table, one needs to utilize the respective degrees of freedom. This involves identifying the appropriate row and column in the F table that corresponds to the significance level being tested (e.g., 5%). [6] How to use critical F values: If the F statistic < the critical F value Fail to reject null hypothesis
Propagation of uncertainty. In statistics, propagation of uncertainty (or propagation of error) is the effect of variables ' uncertainties (or errors, more specifically random errors) on the uncertainty of a function based on them. When the variables are the values of experimental measurements they have uncertainties due to measurement ...