An uninterruptible power supply (UPS) system includes a plurality of UPSs configured to be output paralleled. Availability information is communicated from the UPSs, and an aggregate availability of the UPSs is determined responsive to the communicated availability information. Parallel provision of power from the UPSs may be selectively enabled responsive to the determined aggregate availability. The aggregate availability information may also be reported to a user. The aggregate availability may be, for example, a redundancy level and/or a percentage availability provided by the UPSs. The invention may be embodied as methods, apparatus and computer program products.