How to calculate the signal-to-noise ratios and the standard deviations in the response table for Taguchi design

In This Topic

Calculate the signal-to-noise ratios
Calculate the standard deviations

The Response Table for SIgnal-to-Noise Ratios contains a row for the average signal-to-noise ratio for each factor level, Delta, and Rank. The table contains a column for each factor.

The Response Table for Standard Deviations contains a row for the average signal-to-noise ratio for each factor level, Delta, and Rank. The table contains a column for each factor.

Delta: Delta is the difference between the maximum and minimum average response (signal-to-noise ratio or standard deviation) for the factor.
Rank: The Rank is the rank of each Delta, where Rank 1 is the largest Delta.

Calculate the signal-to-noise ratios

To get the standard deviation for each factor level, consider the following example. You have a Taguchi design where the inner array has 2 factors (A and B), stored in C1 and C2, respectively, and the outer array has two responses, stored in C3 and C4.

Part 1

Choose Calc > Row Statistics.
Choose Mean.
In Input variables, enter C3 C4.
In Store result in, enter C6.
Click OK.

Part 2

Choose Calc > Row Statistics.
Choose Standard deviation.
In Input variables, enter C3 C4.
In Store result in, enter C7.
Click OK.

Part 3

Choose Calc > Calculator.
In Store result in variable, enter C8.
In Expression, enter: 10 * LOGT(C6**2 / C7**2).
Click OK.

Note

You can also get these signal-to-noise ratios by choosing Stat > DOE > Taguchi > Analyze Taguchi Design, clicking Storage, checking Signal to Noise ratios, and clicking OK twice.

Part 4

Choose Stat > Basic Statistics > Store Descriptive Statistics > Statistics.
In Variables, enter C8.
In By variables (optional), enter C1.
Click Statistics.
Check Mean.
Click OK twice.

The last column in the worksheet (named Mean1 if there was not already a column with this name before performing these steps) contains the signal-to-noise ratios that are displayed in the Response Table for factor A.

Repeat Part 4, entering C2 in step 3 to get the signal-to-noise ratios for factor B.

Calculate the standard deviations

Part 1

Choose Calc > Row Statistics.
Choose Standard deviation.
In Input variables, enter C3 C4.
In Store result in, enter C6.
Click OK.

Note

You can also get these standard deviations by choosing Stat > DOE > Taguchi > Analyze Taguchi Design, clicking Storage, checking Standard deviations, and clicking OK twice.

Part 2

Choose Stat > Basic Statistics > Store Descriptive Statistics > Statistics.
In Variables, enter C6.
In By variables (optional), enter C1.
Click Statistics.
Check Mean.
Click OK twice.

The last column in the worksheet (named Mean1 if there was not already a column with this name before performing these steps) contains the standard deviations that are displayed in the Response Table for factor A.

Repeat Part 2, entering C2 in step 3 to get the standard deviations for factor B.