Planning is a very variable thing. Things can happen in a matter of months, or they can take years. Of course it also depends on what level of detail you are talking about. "We want to add a coaster down by the creek some day", is one level of planning. "We've spent $50,000 on a site study, have proposals from 3 coaster companies, have selected the proposal that we prefer, have financing arranged, and have filed a preliminary building permit," is another level of planning. And of course, the amount of planning required for a heavily themed terrain hyper is much greater than what is required for installing a Boomerang.
*** This post was edited by Jim Fisher on 1/24/2002. ***