Questions ref Modeling and tracking off-net portion of circuits in MSS

As a CLEC, we are often required to purchase loops or circuit extensions to get from our network to our customer’s locations.  Ever since we implemented Metasolv 8 years ago, we’ve been using connection crossreferences (Xref’s) as a method of tracking the individual LEC facilities that we’ve ordered to complete the service to our customers.  However, this model falls short of our ever-tightening requirements:

1)      It doesn’t associate the xref to a location or circuit endpoint, which is problematic if there is more than one loop involved per circuit, or if you’re trying to relate external circuit costs to an address.