We have a standard calendar work week. (Monday to Friday with weekends off)
Our resources have "standard" calendar - so scheduling as standard for them is a normal work week.
However, we have operational sub-tasks that sometimes need to happen on a weekend - in non-working hours for our resources. The weekend tasks are dependent on other normal predecessor tasks completing. ie. the weekend task occurs on "the first available weekend after completion of the predecessor task".
From a task perspective this is easy to achieve. We simply create a "weekend calendar" and make the task part of that calendar - the task then naturally schedules itself on the first weekend following completion of the predecessor task/s.
To allow scheduling of the Resources in their "non-working" hours, we on the Task we tick the checkbox Scheduling ignores resource calendars
The Task is created normally and a little red man is displayed in the information column on the left (on the Gantt chart view). Right clicking on the little man causes MS Project to say "Resources assigned in non-working time" - which is fine. This is what we want.
So all looks great.
....until I try to level the resources. At which point MS Project hangs completely and I have to crash out and restart.
It seems to me a basic requirement for a PM tool to cater for adhoc scheduling of resources outside their normal work calendar on dates determined by the natural flow of Tasks (as opposed to saying "on the 5th of May, create this special exception"). And that ticking the "ignore the resource calendar restrictions for this task" should allow this.
I am therefore hoping that I am missing some basic consideration. Any help would be greatly appreciated!