Scheduling Issue

We have a process which involves the production of a certain part
('assembly 0'), which is made up of a 'sub-assembly 1' (this sub-
assembly also has a 'sub-assembly 2'). 1 and 2 each have one
operation, and 0 has two operations. If we have an order for 10
parts, that is ten operations for 2, ten for 1, and twenty for 0.
In real life, as soon as the first operation for 2 has been
completed, 1 can start. And soon as the first operation for 1 has
been completed, 0 can start. However, the scheduling engine wants
to complete *all* the operations for sub-assembly 2, before
operations on sub-assembly 1 and assembly 0 can start.

So if we had an order for 50 parts, it would do 50 operations of 2,
then 50 operations of 1 and then 100 operations on 0. On the plant
floor, we do 1 operation of 2, and immediately start the first
operation of 1, and then immediately start the first operation of 0.

Here is what the scheduling blocks look like on the schedule, and
what they should look like.

Operations for assembly 0: ----- -----
Operations for assembly 1: ----- -----
Operations for assembly 2: ----- -----

I'd appreciate any help anybody could give on this issue!