Database Migration Refactoring

This is a very very sensitve system as if not well handled might broke the whole application , The Current issue is t hat the database migrations in the system are in are arranged in a scattered way with no concern seperation no modularity and full of duplicates which can be further merge arranged and well structure, so that we can now bring and ER diagram for the tables explaining their relation, further more if a change will break the application as it is already deploy, we better leave it as legacy