[whpalmer4]

You do have OmniPlan, right (you referenced OP above)? Why not use that? Do your overall project planning there, and every suitable interval export the next tasks due to be worked on into an OmniOutliner file and import that to OmniFocus for your tactical planning. Unfortunately, you can't send progress/completion data back to OmniPlan from OmniFocus, and in trying this proposed workflow just now, I see there is a bug in how OmniPlan interprets duration information as it imports (1h gets turned into 1 minute).

I haven't done any really massive projects with these tools, but the smaller things I've done I've used OmniPlan to scope out the framework of the project, determine what sorts of resources will be needed and when. I've done individual OmniFocus projects for the individual tasks in the OmniPlan doc where helpful to keep track of the low-level details. I didn't attempt to do any cross-linking between the two apps. Having the OmniPlan framework makes it a bit easier to productively use some unexpected help if the big project has some potential parallelism. And of course it's a bit easier to see how much of an impact a setback will have, which is a rather more likely scenario :-)