If you want to have slugs that are refreshed (updated) each time you change corresponding field in your ActiveRecord models, put this at the end of your initializers/friendly_id.rb file:

module FriendlyId
  module Slugged
    def should_generate_new_friendly_id?
      return true if send(friendly_id_config.slug_column).nil? && !send(friendly_id_config.base).nil?

      change = :"#{friendly_id_config.base}_changed?"
      return true if respond_to?(change) && send(change)

      false
    end
  end
end

This will update slug each time related column (friendly_id_config.base) has changed. Keep in mind, that this method won’t work if you use non-column slug method as a base for friendly ids, since it uses ActiveRecord::Dirty interface.