The responsibilities need to be divided into several modules in order to achieve a functional design.
Every computer system has parts that cannot be functionally pure because they exist to distribute CPU cycles or other resources to different modules.
In some cases, the mixed semantics can extend over a large topological tree or graph of related concepts.
In this context, they mean a parametric model of an object where the parameters are tied to real-world design criteria, such as an axle that will adjust its diameter based on the strength of the material and the amount of force being applied to it in the simulation.
It is hoped that this will create efficiencies in the design process for mechanical and perhaps even architectural/structural assemblies by integrating the results of finite element analysis directly to the behavior of individual objects.