BACnet has provided owners with new and better methods for managing multiple buildings. Before the advent of BACnetbased direct digital control systems, owners tried to select a few vendors of proprietary products, or they installed the same DDC system in all buildings. Restricting competition to a few systems simplifi ed the work of the maintenance department, but created political problems for public sector owners such as military bases, school boards, universities or other taxpayer-funded organizations, who must maintain open competition.