Hello all,

I am assessing the effect of 3 factors on cell viability after cryopreservation in some algae samples. For this, I am using a Taguchi design L18 (2^1, 3^2) and, in 2 runs, I m getting zero viability (this zero is a real one because no cells survived the cryopreservation process). When I try to run the analysis in Minitab, S/N cannot be calculated. However, when I replace these zero values with an extremely low value different from zero (let's say..0.00001%), S/N and all the statistics can be calculated. I m not sure about this approach because the viability in those 2 runs is actually 0 (no cells alive). Is there a suggestion on how to deal with zero values in a Taguchi experiment?

Thanks in advance