Introduction of unachievable NLT constraint slightly extends the schedule

Vladimir,

I am still experimenting with prioritization and I noticed, that when I introduce my favorite NLT constraint into the j3013_8  RCSP then, when resource leveled, Spider actually produces a longer schedule, than without resource NLT constraint. The extension is not big, only 118 days vs 114, but still, since this is the only prioritization I use and I set it to the finish milestone, then I did not expect this to happen, since I thought that all preceding activities would have the same NLT constraint-driven priority.

I must say, that in the past I did not notice such effect of NLT constraint, but I was experimenting only with simple schedules.

Is there an explanation for this?

https://drive.google.com/file/d/0B1FBt_G3gCVqNUE0SEE1Q2VybjA/view?usp=sharing

Regards.

Evgeny.