How best to account for 2 nuisance factors in my DOE: 1 that's quantifiable (tank to tank variability), & 1 that simply accounts for monthly/time-series variation?
If I want to do a (definitive?) screening design with 6 controllable factors in 17 runs (that DOE does not include tank to tank or monthly variation) - what would be the best way to capture the possible error due to those 2 potential nuisance factors? My process involves trying to increase output in a batch reactor process, & I have 4 different reactor tanks & so we can complete 4 runs at a time (...