RE: Keep asset history if resold or bought back
Hi Orjan,
Assuming you sold a machine to a customer A, So the machine is created as asset in Field service and associated with the Customer A.
Now, for all the Services and Inspections of this machines, create the work order associated with the customer A and add asset on these work Order.
When you take the Machine back, update the Customer on the Machine, and if you are servicing this machine even when belongs to you, create Work orders where customer = you and Asset is the same machine mentioned above.
With this you will always maintain how many services were done with this machine. also this will show all the service history with customer associated.
(you can also create a custom Table and store a record as audit when ever Customer is updated on the Asset) useful to know since when to when the machine was with which customer.
This solution we used in rental/ lease model and I think the same can apply here.
Do mark this answer verified if this help.