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What I was trying to do is , to test if optaplanner is suitable for our requirements etc. Thus, I created our own dataset of courses, ~280 courses etc. I "believe" XML I prepared is valid for sample, since it loads and optaplanner can start solving it. However, right during CH phase, it finds some (-220) hard constraint violations, specifically for the rule "conflictingLecturesDifferentCourseInSamePeriod". And for how long it tries, those violations still remain. Then when I check violations, they are actually not real violations. It is two different course, in same hours, but in different rooms, and teachers are not same. So there should be no violation for this scenario. Also actually when I scan schedule by eye, I dont see any conflict. So, I am lost right now....

Here is a link for XML dataset.

Serkan Kasapbaşı
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  • In the example UI, click at the bottom left button "constraint matches", that will give you a dialog. then click on the conflictingLecturesDifferentCourseInSamePeriod line, then look at the lines at the bottom of that dialog. Those line will tell you what exact pair of lectures is breaking that rule. – Geoffrey De Smet Jun 17 '15 at 14:40
  • Actually, I did use this dialog to see the conflicts. However, please have a look at this TDE334{teacher1}-0 @ 4-0 + 437, TDE210{teacher2}-0 @ 4-0 + 435, so, rooms are different, thus this shouldnt be a constraint match. On the other hand, when I check this specific rule, it looks like it doesnt involve "room", then I wonder how other examples can work with this rule. – Serkan Kasapbaşı Jun 17 '15 at 15:11
  • The original rule presumes that a teacher cannot be in 2 rooms at the same time... in this universe at least :) – Geoffrey De Smet Jun 18 '15 at 10:31
  • Actually more generally, he cannot do 2 lectures at the same time (whether or not they are in the same room is irrelevant). There's another constraint that checks that there are no 2 lectures in the same room at the same time (whether or not they are by the same teacher is irrelevant). – Geoffrey De Smet Jun 18 '15 at 10:32
  • Hey Geoffrey, if you check my previous comment, you can see teachers are actually different. – Serkan Kasapbaşı Jun 19 '15 at 08:01

1 Answers1

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Actually I found the problem, well it is not a problem in first place :) Maybe rule name is little bit misleading. Anyway, problem is actually in too crowded curriculums. Like we had 30-40 courses, which makes 80-100 lectures. And for a 45 hours week, it is impossible to fit everything. And I assume the rule "conflictingLecturesDifferentCourseInSamePeriod", checks "different" courses of same curriculum.

So, when I reduce course counts by splitting curriculumns into 4 for each, violations reduced to 0 .

Believe this will be a valuable info to whom couldnt understand mentioned rule's purpose.

Thanks.

Serkan Kasapbaşı
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