The bills of quantities will be exchanged via GAEB (Gemeinsamer Ausschuss Elektronik im Bauwesen: common committee electronics in the building industry).
Info to the data exchange via GAEB: 
The invoice data (quantity entries) are transferred via REB (Regelungen für die elektronische Bauabrechnung: rules for the electronic construction accounting).
Information to the further development of the REB 23.003:
www.reb23003.de
Various interfaces are provided for the data exchange with SAP:
- Project master data
- Addresses
- Performance accruals
- Actual costs
- Procurement budgets
These interfaces are also available for other ERP-systems or can easily be adjusted.
Data between Kubus and other applications, which also have an XML-interface, can be exchanged via a general, flexible XML-interface. An example for this is the exchange of procedure data from Kubus with an application for date and resource scheduling.