Fundamentals > Fundamentals > Relations and Parameters > Parameters > Nonassociativity of User Parameters
Nonassociativity of User Parameters
The values of parameters defined using Tools > Parameters are non-associative. Even if you define the parameter value using a system-defined parameter such as a dimension or mass property parameter, these values do not update upon regeneration of the model. Creo Parametric requires you to add a relation to make parameter values associative.
For example, if you have a cube that measures 10x10x10 units, and if you create a parameter LENGTH = d5, LENGTH is initially evaluated to 10. However, if you modify d5 to 20, LENGTH remains 10.
To associate the parameter value with the model:
1. Click Tools > Parameters and add a parameter LENGTH=15.
2. Click Tools > Relations and add a relation d5=LENGTH.
3. When you regenerate the model, d5 updates to the new value of 15.