Plackett-Burman designs for

PLACKETT-BURMAN DESIGN FOR 7 FACTORS (N=8) AND THE COLUMNS OF CONTRAST COEFFICIENTS FOR TWO-FACTOR INTERACTIONS AND FOR A THREE-FACTOR INTERACTION... 

To test the factors at three levels in a ruggedness test one usually applies the so-called reflected designs [17,19,23]. A reflected design is in fact a two level Plackett-Burman, full or fractional factorial design that is executed twice. Once the design contains the first extreme and the nominal level and once the other extreme and the nominal level. Both designs have one experiment in common, namely an experiment in which all factors are at nominal conditions. A reflected Plackett-Burman design for 7 factors is shown in Table 3.18. 

A Plackett-Burman design for 7 factors (N=8) was applied. The factors are tested at the nominal and an extreme level. They are shown in Table 3.27. 

A PLACKETT-BURMAN DESIGN FOR SEVEN FACTORS OF WHICH TWO ARE CHROMATOGRAPHIC COLUMN FACTORS (MANUFACTURER AND BATCH) IS IMPOSSIBLE... 

B.S. Aswathan and VJ. Victor, Plackett-Burman design for effective screening of process variables, Indian Journal of Technology, 12 (1974) 367-369. 

Table 3 Plackett-Burman Design for Pyridoxal HCL Compatibility Studies...

Table 2. Plackett-Burman design for 11 factors in 12 runs.

This method can be illustrated by taking the Plackett-Burman design for 11 factors in 12 runs, which is based on a 12 x 12 Hadamard matrix and is shown in Table 2. Selecting the rows corresponding to + in Factor 11 and dropping this factor gives the supersaturated design for 10 factors in 6 runs shown in Table 1. 

We have just discussed designs with which we can study the influence of up to 7, 15, 31,...,2 "- factors using 8, 16, 32,...,2" experimental nms. Another class of fractional factorial designs employs a total of 12, 20, 24, 28,... runs to simultaneously investigate up to 11, 19, 23, 27,... factors. With these designs, proposed by R.L. Plackett and J.P. Burman, it is possible to estimate all k = n-l main effects (where n represents the number of runs) with minimum variance (Plackett and Burman, 1946). Table 4.17 presents a Plackett-Burman design for n = 12. 

TABLE 3.4 Plackett-Burman Design for Eight Experiments and Six Facto ... 

To obtain the best experimental conditions for plastic digestion, a 2 Plackett-Burman design for screening the significant factors and a 2 central composite design to optimise the significant experimental variables were carried out. 

TABLE 9 The Plackett-Burman Design for 11 Variables and the Associated Response ... 

TABLE 10 First rows of Plackett-Burman Designs for 8-24 Experiments ... 

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