Rewrite from scratch is a very risky business, especially if it is conducted under the technical view only. The only exception is when the rewrite-team is the s

Rewrite from scratch is a very risky business, especially if it is conducted under the technical view only. The only exception is when the rewrite-team is the same as the original development team, which is almost never the case, except in the continuous delivery model. For me, the consequence is clear: - The rewrite cost is so high, it never justifies to do architectural and software engineering sloppily, even in an agile approach. - Rewrite only critical pieces of software is always a better approach to prefer. In most cases, rewrite just a few pieces of software can satisfy the requirement at least to 80%, be it better performance or higher stability or interfacing with other software. - Therefore, for any big piece of software, modularisation is always helpful.