Options - Elements
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Six Sigma > Design for Manufacturability > Calculate Gap Pools > Options > Elements

Allows you enter the nominal and specification limits for each element; element complexities; diametrical correction factors; and shift and drift factors.

Dialog box items

Complexity: Enter a column containing the complexities for the elements in the assembly. These are the numbers of times that the elements appear in the assembly. The default is set to 1.

Lower spec: Enter a column containing the initial lower specifications for each element in the assembly. If you do not enter initial lower specifications, the values are set, for each element, to (the initial nominal - (4.6505 * initial long-term standard deviation)).

Upper spec: Enter a column containing the initial upper specifications for each element in the assembly. If you do not enter initial upper specifications, the values are set, for each element, to (the initial nominal + (4.6505 * initial long-term standard deviation)). Minitab uses the initial upper specifications to calculate the initial Z-values and PPM's for the elements.

Nominal spec: Enter a column containing the initial nominal specifications for each element in the assembly. If you do not enter initial nominal specifications, Minitab uses the initial element means.

Diametrical correction factors: Enter a column of diametrical correction factors for the elements in the assembly. If you do not enter diametrical correction factors, the default is set to 1 for each element.

Mean shift factors: Enter a column containing the shift factors for the elements in the assembly. If you do not enter shift factors, the shift factors are set up so that each element shifts 1.5 standard deviations toward the nearest gap specification.

Variation expansion factors: Enter a column containing the drift factors for the elements in the assembly. These are the ratios between the long-term and short-term standard deviations for each element. If you do not enter drift factors, these are all set to 1.8.

Long-term Z values: Enter a constant or a column containing values between -7 and 7 to represent the desired long-term Z.Bench for each element in the assembly. These values define the number of standard deviations to use for calculating the upper and lower specs for each element. Minitab uses these values both before allocation (if initial upper and lower specs are not entered) and after allocation.
For example, a Z-value of 4.5 (the default) instructs Minitab to set the:

·    Upper specification at nominal + (4.645 * long-term standard deviation)

·    Lower specification at nominal - (4.645 * long-term standard deviation)