Another difference between Object-oriented design and Model-
Based development is how they handle implementation hiding.
MBD is more restrictive in the accessibility of subsystems than
OO applications. I like how MBD approaches this better than OO
design. I agree with the author that subsystems should be hidden
from one another and only interact through well-defined interfaces.
When I develop software I don't like passing around handlers
all over my application. This is one part of the book where I think
the author really hits it on the nose. Code should reduce dependencies
instead of adding them through implementation hiding.