• Revisions are a part of the Advanced BOMs feature
• Routings are a part of the WIP and Routings module
• Advanced Manufacturing is a bolt on NetSuite product that has it's own tab typically and is used if you're utilizing tablet recording, finite scheduling or rough cut capacity planning typically
To answer the initial question, it is not a native functionality to do this. You can utilize item commitments and a saved search showing shortages to indicate where substitutions are required. You then edit the Work Order directly in the Components tab with the substitution. To automate this would be a customization.