Block DOE Model Issues as Running Experiment (Cell Culture)

Question

I have a cell culture, 5 Block DOE with 6 input process parameters.  The first block showed temperature (one of the 6 input process parameters) to be off from the intended setpoint, but I know the actual setpoint the conditions were run at.  Does this invalidate my entire model?  Or, can I continue?  Or, is it better to do a 4 block design and lose some two-factor interactions?

Mark_Bailey · Answer

There is no issue here. I just wanted to be sure I understood your design and how you actually ran the experiment. Thank you for the clarification.

So simply update the factor levels in the data table before your regression analysis and model selection.

P_Bartell · Answer

@CricciWhat I was suggesting in my initial reply was to compare your originally intended design with the actually executed design. I don't think you'll see dramatic design evaluation characteristics between the two, 5 'block' designs. Then as my former colleague @Mark_Bailey suggests, analyze the actually executed design by substituting the actual levels into the design matrix. My comment around 'inadvertent levels' refers to the single 'block' that had the temperatures run at unintended levels. But @Mark_Bailey 's questions about a 'whole plot' are well taken.

Cricci · Answer

Thank you for your reply @P_Bartell.

I compared the two designs (the current 5 block run with the four block run without a few of the secondary interactions, but it just shows the 5 block design is more optimal, which makes sense because it includes all the secondary interactions.  Or, are you suggesting I make an entirely new design?

I am also confused with your last comment, what do you mean by "inadvertent levels within one block?"