. An article by J. J. Pignatiello, Jr. and J.

S. Ramberg in the Journal of Quality Technology (Vol. 17, 1985, pp. 198-206)

"describes the use of a replicated frac-

tional factorial to investigate the effect of five factors on the free height of leaf springs used in an automotive applica-

tion. The factors are A = furnace tem-

perature, B = heating time, C = transfer time, D = hold down time, and E =

quench oil temperature. The data are shown here.

(a) Write out the alias structure for this design. What Is the resolution of this design?

(b) Analyze the data. What factors influence mean free height?

(c) Calculate the range and standard deviation of free height for cach run.
Is there any indication that any of these factors affects variability in free height?

(d) Analyze the residuais from this experiment and comment on your 1 findings

(e) Is this the best possible design for five factors in 16 runs? Specifically, can you find a fractional design for five factors in 16 runs with higher resolution than this one?

Transcribed Image Text:

ABCDE +1 DI++ ++ 1 ' +1 7.78, 7.78, 7.81 8.15, 8.18, 7.88 7.50, 2.56 7.50 7.59. 7.56, 7.75 7.54, 8.00, 7.88 7.69, 8.09. 8.06