Currently to find a Related Order for an existing order i.e. Backorders created from and Original Order. You need to search every order in the system and check if the RelatedOrderId is equal to the Original OrderId. From there you can create a list of backorders created from the original order.
Searching and returning every order in the system takes a lot of resources.
Each order should provide a list array of orders that have been created as back orders from this original order. This way you can easily interrogate an order and find all the associated back orders.
