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How to do DOE with dependent variables

Hello,

 

I am not sure my DOE is good. I want to compare two different cell culture platforms.

I have two different culture platforms and each plat form has different ranges of rpm and working volume.

For examples, platforms A & B (categorical)

For A, 100 rpm - 200 rpm / 100mL

For B, 300 rpm - 400 rpm / 25mL

Initially, I had two factors like rpm1 (100 - 200 rpm) and rpm2 (300 - 400 rpm). Then, in 'model' I had RSM and removed irrelevant factors like rpm1*rpm2, rpm1*rpm1, and rpm2*rpm2. But I couldn't remove platform*rpm1 or platform*rpm2. I think in this case JMP will do DOE for both platforms with two different rpm , A* rpm(100rpm - 400rpm).

 

Is there any ways I can do DOE properly? I wonder if I can make rpm1 dependent variable to the platform A.

 

 

DOEWindowsRe: How to do DOE with dependent variables

Pardon my possible confusion, but if I understand you correctly you just want to compare the two different culture platforms?  What are the response variables? There are a number of ways to do this comparison, graphically and quantitatively.  But it seems you want something else in addition?  Do you want to assess the effect of rpm on the response variables? Do you want to vary this factor dependent on the platform?  Are there other factors of interest? Your situation sounds as though the rpms are nested in platform.  If so, depending on the amount of data you have, you could do a nested (hierarchical) analysis.  You can do this visa the Quality and Process>Variability Chart>enter the Y's and x grouping (in hierarchy)>choose model type Nested.. When you get the plot you can select the red triangle and go to Variance components.

Re: How to do DOE with dependent variables

@joepark one approach would be to leave RPM in its original (orthogonal, +1/-1) setting. Interpret +1 as high setting and -1 as low setting, regardless of platform. This yields a two factor experiment (Platform and RPM). In addition to full RSM model effects, you may consider adding Platform*RPM*RPM. This term is associate with differences in the curvature due to Platform. The drawback to this approach is that you'll have to hand calculate the actual RPM settings from their coded values. I'm attaching an example.

Re: How to do DOE with dependent variables

Thank you for your suggestion and asking more detail questions!

 

1. Yes. I want to compare two different culture platforms

2. Response variables are viable cell density and titer

3. I want to compare two different platforms and analyze graphically and quantitatively

4. I want to vary rpm and volume for each platform. For example, I cannot have volume over 25ml for platform B. Each platform has different capacity but the factors are same like rpm and volume

5. I expect the main effect would be rpm

 

Can I do DOE with separate dependent factors?

Re: How to do DOE with dependent variables

Thank you for your comment! 

I have some follow up questions.

 

1. on the example file, there are 3 RPM designs -1,0, 1. If my experiment RPM range is 100 RPM to 400RPM then, DOE tells me to test 100RPM(-1), 300RPM(0), and 400RPM(1)?

 

2. In my experimental condition, platform 'A' RPM range cannot exceed over 200 RPM and platform 'B' RPM range cannot be lower than 250RPM. Give the condition, Platform*RPM*RPM would still consider different range of RPM for each platform?