An apparatus is disclosed for testing a utility computing system having a plurality of hardware and/or software planes. The apparatus comprises a plurality of administration units, each administration unit being arranged to carry out test operations on a utility computing system during use, and each administration unit having associated access details usable to gain access to at least one plane of the utility computing system during use, an authenticator arranged to receive access details and to permit or restrict access by an administration unit to one or more planes of the utility computing system during use depending on whether the received access details correspond to the access details associated with the administration unit, and a dispatcher arranged, for each administration unit, to automatically forward the access details associated with the administration unit to the authenticator so as to thereby permit the administration unit to gain access to one or more planes of the utility computing system during use and carry out test operations on said accessed one or more planes.