First, welcome to the community. I'm not sure I understand exactly what you want and from which platform you are using to create your mixture design, but you can certainly do linear constraints and set the value after the ≤,≥ sign in the DOE>Classical>Mixture Design platform:
![Screenshot 2023-03-15 at 10.28.43 AM.png Screenshot 2023-03-15 at 10.28.43 AM.png](https://community.jmp.com/t5/image/serverpage/image-id/51096iBA9C19D949D7EDEF/image-size/medium?v=v2&px=400)
You can also do this in the Custom Design platform after you have added your mixture factors.
![Screenshot 2023-03-15 at 10.32.28 AM.png Screenshot 2023-03-15 at 10.32.28 AM.png](https://community.jmp.com/t5/image/serverpage/image-id/51097iC9AB35D26C2A3509/image-size/medium?v=v2&px=400)
"All models are wrong, some are useful" G.E.P. Box