Page 238 - Design for Six Sigma a Roadmap for Product Development

DFSS Transfer Function and Scorecards 209

consult with their MBB for complexity-customized equations. A
scorecard, say, s, complexity is the sum of entries in column 7:

m s
h(scorecard s )
h(FR i )
i 1

m s
2

ln 2 e
i 1 FR i
The sum of the complexity column in all hierarchal scorecards of a
structure gives the structure complexity estimate as

N
h(structure)
h(scorecard s )
s 1

(where N number of scorecards).The sum of the physical structure
and the process structure complexities is the design complexity.
Other forms of complexity are derived by El-Haik and Yang (1999).

The objective is to reduce complexity per axiom 2 by decreasing
the variance of the FRs while achieving Six Sigma capability.
8. Enter the target of the FR as obtained from the phase 2 QFD.
9. Enter the lower FR specification limit (LSL) as obtained from the
phase 2 QFD, if applicable.
10. Enter the upper FR specification limit (USL) as obtained from the
phase 2 QFD, if applicable.
11. The predicted FR capability for the mean is entered here as esti-
mated from Eq. (6.9), sampling, or historical long-term data.
12. The predicted FR capability for variance is entered here as esti-
mated from Eq. (6.8), sampling, or historical long-term data.
13. Enter (L) for long and (S) for short if the sampling was used.
14. Calculate the Z value.
15. Use the historical shift if available, or estimate.
16. Use the tables to calculate the DPMO.
17. Record the historical mean of the FR, if available.
18. Record the standard deviation of the FR, if available.
19. Enter the sensitivities in the matrix as derived or obtained from
the transfer function sources in Sec. 6.4.1.
20. Enter the ideal function sensitivity as derived or obtained from
Sec. 6.4.1 transfer function detailing methods.