Turnkey: Pertaining to a procurement process that (a) includes contractual actions at least through the system, subsystem, or equipment installation phase and (b) may include follow-on contractual actions, such as testing, training, logistical, and operational support.

Note: Precise definition of the types of allowable contractual features are contained in the Federal Acquisition Regulations (FAR). Source: from Federal Standard 1037C and from MIL-STD-188