How to deal with CIP assets that related to multiple inovices?

Summary:

We want to know if we handle the cip assets that releated to multipe invoices in the right way.

Content (required):

The case is that we have CIP assets , the assets for example is about 500 PC , the supplier supply all units to our location but the total due amount of invoices are not paid once(two payments), so when transfer the first invoice from payable to assets module, the buisness user add this invoice to asset(via add to asset button) then split it into 500 asset(the same of # units) so the system give each asset (each PC) the same cost(whic is not true since the total payments are not done yet) when the second payment is reached the