Ability to associate Purchases with Business Applications

Hi

We are starting to associate costs with items in D42, but when creating a Purchase and adding a Line Item, the option to associate the cost with a Business Service is not there. In the "Item Type" drop-down Business Application is not listed, you also can't create the link to a Business Application like you can we a device or asset.

This seems an obvious thing to have as we'd link to document support purchase costs, without it we are missing a big part of the cost of a Service.

Thanks

Andy