[Ramshackle]

How do I indicate a project or task that has a preferred start date, but whose start is delayed?

An example of this:
Let's say I am building a large product & tracking tasks to complete it.
I have a ship date for the product as an end date.

There is an ETC which I need to use as my target schedule.

I have an 8 week lead time for a project task, perhaps a subassembly that needs to build fabricated by an outside machine shop.

They have a lead time for materials & they need to schedule the machine time.
However, the task did not begin on time. Perhaps the quote process was delayed & they will be starting a week late.

One is a valid projection & the other is real life timing. At some point, they could converge & the task be on schedule again. Its essential for me to track both those dates.

How do I manage this?

[Lizard]

This almost sounds more like OmniPlan than OmniFocus.

In OmniFocus, a start date is (for many of us) more of a "can't start before this date". So I'd set the start date to that 8 weeks date. Then when I hear they're behind I can move that start date. You *could* track that change by adding a note "8/1/13: Delayed 3 weeks because the [pre-req] ran out of rivets." That's more informative than just 2 static dates.

Maybe if it's really important, I'd set up a weekly repeating task "check in on progress of [pre-req]".