turnkey project

noun
  1. engineering a complete project usually including many major units of plant completed under one overall contract, such as a chemical works or power station complex

Word Origin for turnkey project

C20: from use of turnkey in the construction industry to describe the day a job will be completed and the owner able to turn the key in the door
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012