A turnkey or a turnkey project is a project in which a separate entity is responsible for setting up a plant or equipment (e.g. trains/infrastructure) and putting it into operations. It can include contractual actions at least through the system, subsystem, or equipment installation phase and may include follow-on contractual actions, such as testing, training, logistical, and operational support. It is often given to the best bidder in a procurement process.
Turnkey projects can also be extended, known as turnkey plus, where there is perhaps a small equity interest by the supplier and it will later on continue its operation through a management contract or licensing.
The term turnkey is also often used in the technology industry, most commonly to describe pre-built computer "packages" in which everything needed to perform a certain type of task (e.g. video/audio editing) is put together by the supplier and sold as a bundle. This often includes a computer with pre-installed software, various types of hardware, and accessories.
Note: Precise definition of the types of allowable contractual features are contained in the Federal Acquisition Regulations (FAR).
Turnkey means to provide complete solution of problem