A Gantt chart charts out time on the X axis and tasks on the Y axis. It's a project management tool that you can use for just about anything and there is, of course, tricky software to do it. Microsoft Project is what I use, but Excel works fine for small stuff. One of my many IT jobs in my past life was as a project manager. Unfortunately, or fortunately, nobody else except other project managers could read the chart. It made me look really smart with management (not hard to do), but it didn't exactly make me the great communicator. A Gantt chart looks something like this:
The key points is that you can assign dependencies. For example, I need to order toys for the new toy section. I can attach it to the fixture delivery task or the delivery "milestone." This means that if the fixture date gets moved, I automatically bump forward my toy deliveries by that amount of time. You need to have fixtures before you get your stock. Before the fixtures arrive, I need to have the carpet in, otherwise I'm moving stuff from room to room while my annoyed carpet installers stand around and grumble (getting them coffee helps). Before the carpet is in, the painting needs to be done, unless I want paint splatter on my carpet. Before the painting needs to be done, the new dividing walls need to be built, important since I'm getting free paint from the landlord - I might as well paint the whole space, right? I can't do any of those things until I take possession of the space on August 1st. So it all links together in a very happy and complicated diagram that only I can read.
While that linked chain of dependencies plays itself out, I'm also doing other tasks. We need a completely new exterior sign. We need another 4x8 table built. We need several licenses and permits (business, alarm, sign). We need to change our advertising. The phone service needs to be installed (we couldn't keep our old number, unfortunately). It's actually kind of fun, mostly because it's predictable. What's scary are the unknowns. Will there be ancient Indian artifacts under the floor tiles? Will the city deny our business license for "games" because they think we're going to run a casino? A day into the two day move, will we discover we've got a weeks worth of moving work?
The neat thing about the Gantt chart is that you can watch your project implode with great detail. I know this from managing projects in IT. Often, the best thing you can do with your fancy chart is place blame. "It's really clear by this half blue bar on line 154 that the networking department was to finish installing BGP4 routing by June 1st." So yes, a Gantt chart is really about CYA. This is especially important in project management in a big company because you usually have no control over the people doing the work. The best you can do is implore their managers to motivate their staff. The worst case scenario is to blame a bad manager in front of their boss or peers for not giving you the available resources. Of course, CYA when you have your own business is pretty worthless. Failure is really not an option.