priority vs. locking
 

We found a problem with one of our products and it was necessary to fix that before resuming development on new stuff. I created a task for this new work. Is there a way to set some priority to that task so that it is scheduled first, or do I have to lock the start time to make sure it appears first? (I want that developers scheduled to get rearranged as best as possible with this new task at the beginning.) I suppose levelling his others tasks would work too, but I feel that some kind of priority system might be more elegant.

OmniPlan does have a priority feature. You can access it by going to "View" -->"View Options" and checking the "Priority" box. This will display a priority column in the task outline.

Once you have assigned a priority value to your task, it won't automatically get rearranged to the beginning until you level the project.

Ah, that is perfect and works exactly as I expected. I guess I just missed it. Thanks.