Hi Riccardo,

From the routes per se, it seems to be configured correctly and difficult to point precisely the issue. My suspect is Transit location, it seems to be central and same for returns, rental as well as regular sales routes. It is likely that the rule sequence Pull from Transit to Customer (sales routes) is lower and gets triggered, with other 2 routes.

You might want to simplify the 3 routes and then validate if routes are triggered as intended. Basic 1 step for each, then 3 step for delivery; 1 step return (excluding the transit location). This might help isolate the issue.

== Yes, your understanding of Supply Method is correct. Take from stock would reserve product only at source location. Trigger another route would create subsequent route. Take from stock (source location), if unavailable trigger another rule is the 3rd option that combines both.
The issue here seems to be the trigger of a different rule and not with reservation.

1. It is still unclear how the rental orders are differentiated from regular sales on the Sale order to trigger the delivery route.

2. How is the return of rental product triggered? By clicking return on the delivery order (Receive operation in your case) would only create a single inventory operation, while you wish to have a 2 steps route with a Pull rule.

Thanks

I can confirm that rental location is set as internal location. And yes, you are right, as soon as the equipment is delivered, the items are available at the customer/Rental location. That's might be a good reason why this location is for odoo the nearest option to deliver during a Sale Order. For now, I use the workaround to force a route_id for sale delivery (Stock --> Customer) on sale.order.line, but that doens't feel the correct way.
I am still wondering how odoo decides to use a location as Removal location. Somehow I want odoo to tell, that only stock an appropriate removal location, and not the customer location.

As default Odoo uses Partners/Customers as customer location to trigger delivery routes (Stock -> customer). It is not clear how your configuration is for the Partners/Customers/rental to be the default for deliveries (Customer -> Rental).

Also, how is the rental return route triggered?