With this procedure, you can fill in the lines of a service invoice with the selected posted shipment lines for a specific customer. This will enable you to create an invoice for the items that have already been shipped (either from one or several service orders) but not yet invoiced or consumed.
Open the 
Service Invoice
window.
Place the cursor in the No. field and press F3 to create a new service invoice, and then fill in the document header.
Click Functions, Get Shipment Lines.
In the Get Service Shipment Lines window, select the relevant shipment line(s), and then click OK to insert the service shipment line(s) on the invoice.
The program will now automatically insert the selected posted shipment line(s) into the invoice for the specified customer.
Invoicing Posted Shipment Lines