Constrained design of experiments

#1
Good evening!

I would like to conduct a 2-level fractional factorial experimental design on 8 factors. I used the FrF2 package in R to do so. I have capacity to do roughly 30 experiments, so I selected a resolution IV 2^(8-3) with one center-point. Repeats aren't necessary for reasons related to the quasi-computational nature of the experiment. Upon inputting the values to the machine controlling the experiment I realized the following. Two of the factors, call them A and B, would normally have (A,B) permutations equal to (False,False), (False,True), (True,False), (True,True). However, the (True,False) combination does not make physical sense - it is impossible. But the other three combinations do make sense and I would like to test them. I am unable to find information on how to properly account for this case to design an efficient experiment with few aliases. Any help with this would be greatly appreciated.

Thank you - Matt
 
#2
Skip an other level of the three levels and you will have just two levels. That is your two factor experiment is redused to one factor.

To do factorial experiments is to do compromises. You can't get everything.