For example, if you want to choose the best of several materials, you can assign it to the L18 orthogonal table . Normally, the L18 orthogonal table is an allocation table with 2 levels for column A and 3 levels for columns B to H. Up to 6 types can be assigned to the L18 orthogonal table.
Please see the material. → QE21
Combine columns A and B, and divide the levels into 1 to 6 in 3 rows as shown in the table on the right. It's a fairly convenient method. It does not have to be a numerical value. It is effective when you want to compare and examine materials 1, materials 2... material 6, method 1, methods 2... method 6 anyway. Of course, we should evaluate by SN ratio (stability).