Ramp-up was originally an auto industry term used to indicate when a new model was scheduled to ship out, deliver, or "ramp-up" onto auto vehicle transport trucks. Also may used in other contexts, such as when a business switches over to or begins using a new software package or new version of older software. The term ramp-up was used primarily in a time context, when something was due to occur or occurred in the past.
The news media misconstrued the meaning of ramp-up a few years ago, when interviewing auto industry people, to be synonymous with "ratchet-up", meaning to increase or "turn-up". The term is now used almost exclusively in this context.
The Chevrolet Volt is scheduled to ramp-up in late 2010.
Our company will ramped-up its new accounting software package next month.