The United States Department of Defense chooses to use the term initial operational capability when referring to IOC.
[2] For a U.S. Department of Defense military acquisition, IOC includes operating the training and maintaining parts of the overall system per DOTMLPF, and is defined as:"In general, attained when some units and/or organizations in the force structure scheduled to receive a system have received it and have the ability to employ and maintain it.
Declaration of an initial operating capability may imply that the capability will be developed in the future, for example by modifications or adjustments to improve the system's performance, deployment of greater numbers of systems (perhaps of different types), or testing and training that permit wider application of the capability.
Alternatively the specifics of the program may cause a contract and acquisition-defined definition that differs from the concept of available in minimally deployable form, for example IOC on a website, which does not have material production or maintenance, may have been defined as when the training mockup is installed rather than when software or content is ready.
(Both of these are meaningless to formal program state or contractual actions, but the progress or event are meaningful in other senses.)