Products that have become too complex to management, services and SILO’s that’s just patched and patched and finally makes no sense or outright crazy to manage.
These are all cases for re-engineering.
Re-engineering happens to be effective adaptive word for systems re innovation, a simple example can be found in the banking systems.
They are doing essentially the same thing, but operating more efficiently.
That’s one of the goals of re-engineering.
Speaking of banking example, banks decided at some point that the majority of the transactions involving cash can be optimized by putting an automated teller machine. So the resource called cashier had much less to do and the customers who were there only for cash withdrawal can now, just use the ATM’s and be out of the system.