Plackett-Burman

An example of a Plackett Burman plan for Z = 2 levels, m = 7 influence factors (including dummy variables) and, therefore, N = 8 runs is given in Table 5.10. 

Table 5.10. Plackett-Burman design matrix lor N 8 experiments and consequently m = 7 factors (including dummy variables) at two levels... 

If nonlinear effects are expected the variables must be varied at more than two levels. A screening plan comparable to the Plackett Burman design but on three levels is that of Box and Behnken [I960]. 

Because of the complexities involved in understanding cause-effect relationships, an alternative approach to control the thin film microstructure has been pursued by some investigators—the use of statistically designed experiments to identify key processing parameters.114115 In these approaches, as illustrated in Table 2.6 for a Plackett-Burman screening study,114 limiting values for various experimental parameters are chosen. Films are then prepared from solutions synthesized under these conditions, and resulting film... 

TABLE 7 A Plackett-Burman Design in Which Eight Factors are Studied Simultaneously in 12 Experiments... 

TABLE 8 Example of a Plackett-Burman Experimental Design to Evaluate the Effect of varying Seven Conditions on Method Robustness... 

ASTM El 169-89 Standard Guide for Conducting Ruggedness Tests (Plackett-Burman Design), American Society for Testing and Materials (ASTM), 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959. 

TABLE 7 Plackett-Burman Design to Examine up to Seven Factors in Eight Experiments... 

TABLE 9 Results of the Eight-Experiment Plackett-Burman Design ... 

Plackett-Burman design. (----) least-squares line through all effects (-) assumed line through... 

Vander Heyden, Y., Hartmann, C., Massart, D. L., Michel, L., Kiechle, P., and Ernl, R (1995). Ruggedness tests for a high-performance liquid chromatographic assay comparison of an evaluation at two and three levels by using two-level Plackett-Burman designs. Anal. Chim. Acta 316, 15-26. 

The relationship of saturated fractional factorial and Plackett-Burman designs. 

The foldover design for the Plackett-Burman design in Table 14.9. 

An 11-factor Plackett-Burman design with foldover. 

Plackett-Burman and saturated fractional factorial designs. 

Using row and column operations, convert the following 7-factor Plackett-Burman design to the saturated fractional factorial design shown in Table 14.7. 

The second approach is to perform traditional pre-formulational studies using full factorial or Plackett Burman experimental designs [15]. Here, the preferred analytical methodology tends to be thermal and spectroscopic, rather than chromatographic, although the latter methodologies are still utilised. Differential scanning calorimetry (DSC), isothermal calorimetry (ITC) or Fourier-transform infrared (FT-IR) spectroscopy have all been utilised successfully. 

Plackett-Burman k factors k+i Greatly reduced number of experiments ... 

Screening 6-40 Identify important variables. Estimate approximate effects. Plackett-Burman (PB) 2 Fractional feaorial (FF)... 

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