Definitive Screening Design Workflow

[#1]

Hello,

I ran a Definitive screening design and generated a table by selecting "Add block with center runs to estimate quadratic effects. I collected the response data and added it to the table. But when I try to run "Fit Definitive Screening", I'm met with this error:

The Fit Definitive Screening platform only runs when I hide/exclude runs from block 2. Am I doing something wrong? How do I run a model with all of the runs included? Do I have do some kind of augmented design to include the second block?

[#2]

Hi @sanch1,

I just tried to reproduce the same error by creating the same design type with 8 continuous factors, 2 blocks, 8 extra runs :

When using a random formula to model a response with this design, I have no error and can continue the analysis :

I have the same design as you (you can also find it attached) :

Normally you would get this error message when one or several experimental runs are not part of the design and destroys the foldover structure, see https://community.jmp.com/t5/Discussions/How-can-I-add-extra-runs-into-the-designed-runs-from-Defini... 

There are many other ways to proceed with the analysis using the Fit Model platform if necessary, using Stepwise models, Generalized regression models, etc... 

But in your case, row 18 is perfectly fine and is the "mirror image" of row 17 in the same block 1, so the foldover structure is present and respected.

Did you change any factors values in this row (or in others) after generating the design ?

Did you try launching the "Fit DSD" platform from the menu (menu DOE, Definitive Screening, Fit Definitive Screening) ?

Can you share an anonymized version of your dataset and design ?

Hope this first discussion starter might help you,

[#3]

Hi Victor,

I did make some changes to the table:

1. I sorted the data table ascending by block for organization

2. The experiment in run 19 I had to remove due to it failing before I could collect results.

would either of these have threw off the DSD design?

[#4 · Accepted solution]

Hi @sanch1,

Sorting the datatable don't change the design structure and analysis. However, removing an experiment from the table will destroy the design foldover structure (there will be one experimental run without its "mirror image" counterpart, which prevent from using the Fit DSD analysis platform). You will face the same problem and error message with response missing value(s), or by excluding row(s) in the table. 

I have the same error message than you when removing any run from the design table and trying to launch the Fit DSD platform :

I would recommend using other modeling platforms (as mentioned in my response before) to do the analysis.

Hope this answer your question,

[#5]

I went ahead using a method with the All possible models approach through Stepwise. Thank you so much for your help!

[#6]

Pardon my comments (and ignore them if you prefer), but stepwise is not how you should analyze DOE.  Stepwise is an additive model building approach useful when you don't have a model in mind (e.g., data mining).  When you run experiments you start with a model in mind.  This is a function of the factors and levels (and strategies for handling noise).  From the model you started with, you remove insignificant terms (a subtractive approach).

[#7]

Interesting approach! However, given this particular approach where I have one data point (as I wasn't able to complete that run), what would you recommend instead to get anything useful out of the data I still have?

[#8]

Sorry, I haven't been following the whole thread and I saw Victor was giving advice so I didn't comment.  You ran an experiment with a set number of factors and levels.  Apparently you also decided to run blocks and center points.  Regardless, you should have a model assigning your DF's.  And you should absolutely analyze the data with that model.

See my advice from this thread regarding missing data:

https://community.jmp.com/t5/Discussions/JMP-DOE-chromatography-data-table-How-do-I-enter-values-for...