Redistributing numbers

[mlogan]

Hi RobPratt, I ran your whole code and it gives me the following table. Should I get rid of any part of your code? Thanks.

COURSE	ROOM_NO	ROOM_CAPACITY	ROOM_LOAD	NEW_ROOM_LOAD	Room_Status
CHEM101	C101	20	7	20	Available
CHEM101	C102	20	11	16	Available
CHEM101	C103	10	8	0	Available
CHEM101	C104	15	10	0	Available
BIO302	HB102	22	20	22	Available
BIO302	HB106	24	12	24	Available
BIO302	HB902	30	29	30	Available
BIO302	W102	30	31	30	Available
BIO302	AB102	40	27	13	Available

[RobPratt]

Did you get any error message in the log?  I suspect that your SAS version does not support indicator constraints (IMPLIES), in which case you should instead use the second (commented out) version of the RespectCapacity constraint.

[mkeintz]

@RobPratt 

It appears to me that your OPTMODEL code maximizes the total number of SEATS available in unused rooms.  Do I have that correct?

But the OP appears to ask to maximize the number of unused ROOMS (minimize number of rooms used, actually).  Could there not be a configuration of room sizes that satisfy your objective but would not satisfy the OP's original request?  

For instance, if there are six rooms with sizes 7, 6, 6, 5, 2, and 2.

1.   For total load 13, I believe your code would select a 7 and 6, maximizing the number of seats in unused rooms (6+5+2+2=15).  And that result would also satisfy the objective of maximizing unassigned rooms.
   
   
2. For total load 11, I think your code would use three rooms (7, and both 2's,) leaving 3 rooms (6+6+5=17) unused, maximizing seats in unused rooms.  However, the minimum number of ROOMS needed for the total load would be two (7 and either 5 or 6), leaving 4 rooms free, but with smaller total capacity.

Maybe the OP doesn't care about this issue.  But is there code that would do two levels of optimizing?First, minimize the count of used rooms.  Then, for all combinations satisfying that objective, find one that maximizes your objective - total seats in unused rooms.

[RobPratt]

@mkeintz Yes, I included both objectives, with one of them commented out.

Yes, you can optimize multiple objectives sequentially, with a primary objective, secondary objective, tertiary objective, and so on.  Here is one such example: SAS Help Center: Distribution 1: Which Factories and Depots to Supply Which Customers