Total Cost of Ownership (TCO)

Gartner defines total cost of ownership (TCO) a comprehensive assessment of information technology (IT) or other costs across enterprise boundaries over time. For IT, TCO includes hardware and software acquisition, management and support, communications, end-user expenses and the opportunity cost of downtime, training and other productivity losses.

Reference from http://www.gartner.com/it-glossary/total-cost-of-ownership-tco/