In the 90s the CLARiiON organization had moved from a text-based management tool (Gridman) to a remote command line interface (CLARCLI) and a remote graphical user interface (ArrayGUIde). I wrote in a recent post that I was offered the opportunity to replace these tools by building a new storage management architecture from scratch.
This new architecture became what is currently known as Navisphere, and yes, it was a complete re-write. Complete re-writes are a pretty drastic step.
But it was necessary.