I have to design an experiment where tool wear is a factor (not a response). I'm not trying to study tool wear minimizing. I'm trying to study the effect of tool wear along with 3 other factors on the number of a certain defect type.
What kind of design should I use? I considered dividing the tool wear into 3 conditions (low, med, high) and then running each treatment within the conditions. But I'm not sure that is a correct method. Tool wear is considered to be a highly significant contributor to the defect rate. Interactions are also important here.
This is a forging operation. The other factors are billet temp, spotting location and pancake height. I have plenty of replication opportunities and plan at least 10 parts for each treatment.
Many Thanks - Kelly