Factor variation level

Having selected the system response, we start choosing factors, levels of the factors and center point of the design (basic level or the null point). By factor we understand the controllable independent variable that corresponds to one possibility of influence on the object of research. A factor is considered defined if its name and domain of factors are determined. A factor may take several values in this field. The chosen factor values, both qualitative and quantitative, are called factor variation levels. Factor variation levels in the design of experiments are coded values. Under factor interval of variation we understand the difference between two factor levels, which in their coded form have value one. When selecting the factors one should pay attention to the conditions they must meet. 

The presented block diagrams link the factor-fixing accuracy, range of response change and response-surface curvature with the width of factor-variation interval. When selecting a factor variation interval one should, if possible, account for the number of factor variation levels in the experimental domain. Depending on the number of these levels, are the experiment range and optimization efficiency. 

Name and mark of factor Variation levels Variation interval e... 

When all possible response values are available for all combinations of factor variation levels in the form of a table, there is no problem to define or select... 

To optimize the process of isomerization of sulphanylamide from Problem 2.6, a screening experiment has been done by the random balance method. Factors X1 X2 and X3 have been selected for this experiment. Optimization of the process is done by the given three factors at fixed values of other factors. To obtain the second-order model, a central composite rotatable design has been set up. Factor-variation levels are shown in Table 2.148. The design of the experiment and the outcomes of design points are in Table 2.149. 

III Mixture Design Composition-Property Table 3.52 Factor variation levels... 

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