Hi Dan Rumney. Thanks for your inputs. Appreciate it.

Sorry, if I give the impression the principles break down. They are great principles. There’s nothing really faulty about them.

What I’m trying to clarify is, applying these principles, doesn’t mean one will not need to change anymore from the core of the structure adhering to the principles.

In the LSP example, I can choose to break the principle by making Animal still works for the function, but then break LSP (e.g. having an additional function or exception condition), or I just change the Animal to still adhere to LSP, but show that the function will fail to work. Both will still show there need to change.

I chose the latter just to ensure I don’t break LSP, but still, then changes are needed.

Again, let me reiterate. The principles are great principles to adhere to. Just that it’s not a silver bullet to make our class/architecture rock solid and don’t need changes anymore (which many people have the perception of, think this is what SOLID Principles is for, as per the acronym gave that impression).