You can add Routings on Manufacture / Products / Routings

#. Create new Route
#. Add Operations
    Operations its a copy of current operations on BOM,
    with field "On template change?", this is Sync as default,
    in this mode every change on this template is propagated
    on operations related with this template

Configure BOM and and Operations Page you can select predefined route (there are two ways to configure with templates)
  - You can select a predefined route,
    and this action replace and populate with templates associate
  - Or You can add operations and select operation
    as template to help setting default data

On both configurations you can set field "On template change?" that change behavior when template related perform changes on data
