Running a DOE with an S shaped response (Cubic)

An answer to a viewers question about how to deal with a DOE when the system response might be cubic...
The Blackbelt Handbook - www.lulu.com/shop/paul-allen/...
If you like these video lessons. Here is my buy me a coffee link.
www.buymeacoffee.com/osId2T0BL
Here is a free D.M.A.I.C users guide - Click the link and download it now! paul-allen.mykajabi.com/dmaic...

[@jonathanandrews807]

Dear Paul, thanks so much for creating both this video and the model you kindly sent. Most helpful!

[@mikemotorsport]

I would be interested to see his gage r+r results before coming to such an involved doe model. A follow up video would be interesting on this.

[@paulallen5321]

Hi Mike - yes good input. I think I would want that data as well. Although now we have the DOE data, if the model it creates confirms, then the measurement system must be working ok. Also the graphs he sent over over move nice and smoothly as time is increased. So I have some confidence in this data. But I've sent him the model now and I'm waiting for the confirmation test results

[@ericstefko4852]

The second curve (top right) looks like a logarithmic function, am I missing something?

[@paulallen5321]

Hi Eric - There are lots of mathematical functions that could describe a curve the traditional one of the sq function or quadratic. These days software tends to group them as polynomial...