Many of our projects (construction projects) result in having multiple invoices generated from a single estimate as forms of interim payments for works completed during a certain period (ie monthly). Currently the moment I create an invoice from an estimate, no matter the value, the estimate status is changed to INVOICED. But if the invoice value is less than the estimate value what would be more beneficial is to have the estimate status shown as PARTIALLY INVOICED. Once the combined invoice values linked to an estimate matches that of the estimate value, only then should the estimate status be INVOICED