usage begins
Operation begins in at least one of the assigned uses of a structure or other object.
The usage of a structure begins when any one of its assigned uses becomes operational. In many cases this occurs slightly after the first tenants move in (for example when a store moves in but has not yet opened to the public). Usage can refer to any available assigned use, including transmission from a signal tower, public visibility of a sculpture, or the opening of a hotel to the first guests.
One assigned use becoming operational is sufficient; every planned activity need not start simultaneously. A partially opened building can therefore have a usage-begins event.
Moving tenants or equipment into place can precede operation. The event follows the start of the actual assigned function, which need not involve visitors entering an interior.