Model-based systems engineering is a useful tool for things like designing rockets.

You take the time to create an extremely precise model of the physical constraints of the system.

This allows you to see precisely how a change (for example, the tolerances of one component) would affect other components, in a tree of effects.

Why isn't it used more often?

Because it requires significant up-front modeling.

This can make sense depending on:

This technique works in physical systems where interactions can be precisely modeled, but could not work in complex adaptive systems.