Hi @AnkeWoest 

Did you already take a look at robust optimization or stochastic programming as an alternative?

If this is a project please send it to support@aimms.com and we will get back to you. 

Best

@AnkeWoest , you can generate data using functions like Demand(i,j,k) := Uniform[10,30]. Each time you run it, a new set of Demand data is generated.

You can also use a parameter as upper and lowerbound. More functions are available; see e.g. https://documentation.aimms.com/functionreference/elementary-computational-operations/distribution-and-combinatoric-functions/index.html