For example, if the stock is below a certain value, you can setup odoo, so it creates purchase.order it self.
Now I want to add all (or a random) user(s) with permission "pruchase => manager" to the followers (So he gets an E-Mail: There is a new objectX).
I would prefere to set it up in "Settings => Technical" or install a plug-in. If neccessary, I also could change some code, but my background is PHP, so I would need some description, how to write a plugin myself, because i still want to be able to upgrade my package.