Thanks Rob!   We actually were doing a data solution and not even asking the solver to solve it, which was a little inefficient in cases where it could better make choices on how to fill trucks. As we add more and more to this problem I suspect we'll have to let the optimizer solve the best way to split trucks out. ... View more

Does not need to be equal, just needs to be able to split when demand is greater than capacity of a truck. ... View more

I was wondering if that was necessary since it would clearly be true when nothing was assigned to it. I'll add it in if it will make things easier on the optimizer. Thanks! ... View more

I believe this constraint: con rdc_bin_con {i in RDC}: &rdcMINZip3Cap <= sum {<(i),j> in ARCS} assignFlow[i,j] <= &rdcMAXZip3Cap; was causing the issue. It was effectively never allowing for 0 sites to be assigned  to a facility, so I fixed it by breaking it apart and including and multiplying the lower bound by build[i]:   con rdc_serv_max_con {i in RDC}: sum {j in ZIP3} assignFlow[i,j] <= &rdcMAXZip3Cap; con rdc_serv_mmin_con {i in RDC}: sum {j in ZIP3} assignFlow[i,j] >= &rdcMINZip3Cap * Build[i]; Still churning, but I believe that is the issue. ... View more

I see so it is only assigning flow to the smaller set of facilities, but still saying to build them all. So I must have something wrong with the general problem formulation. Back to the drawing board. ... View more

Results for build solve: i   1352485 25 1353588 25 1358063 25 1360697 25 1360742 25 1360762 25 1367260 25 1368208 25 1372672 25 1380388 25 1380428 25 1380602 25 1382577 25 1432873 25 1432887 25 1433257 25 1433414 25 1433529 25 1433530 25 1433589 25 1434840 25 1435567 25 1435750 25 1436570 25 1438171 25 1439777 25 1440140 25 1440579 25 1440968 25 1440974 25 1440977 25 1441024 25 1441025 25 1441026 25 1441029 25 1441030 16   Results for both running: i   1352485 6 1353588 1 1358063 6 1360697 7 1360742 5 1360762 5 1367260 5 1368208 5 1372672 4 1380388 6 1380428 3 1380602 3 1382577 6 1432873 6 1432887 6 1433529 5 1433530 5 1433589 2 1434840 3 1435567 6 1435750 3 1436570 1 1438171 3 1439777 8 1440579 2 1440968 6 1440974 8 1440977 5 1441024 3 1441025 6 1441026 11 1441029 3 1441030 6 1441032 4 1441038 6 1441040 9 1441043 3 1441044 6 1441050 2 1441051 1 1441052 4 1441053 1 1441057 5 1441059 3 1441060 6 1441061 3 1441062 4 1441064 4 1441067 3 1441076 5 1441078 6 1441081 5 1441082 6 1441083 2 1441088 6 1441091 6 1441099 2 1441101 6 1441102 3 1441104 3 1441111 6 1441116 8 1441119 6 1441120 7 1441124 4 1441133 9 1441134 7 1441140 7 1441150 6 1441162 8 1441174 10 1441177 8 1441182 5 1441184 3 1441185 6 1441190 6 1441191 6 1441192 3 1441198 3 1441199 3 1441203 1 1441207 2 1441215 6 1441227 9 1441229 6 1441234 8 1441239 6 1441241 6 1441242 7 1441254 5 1441257 6 1441258 6 1441264 4 1441267 6 1441272 7 1441281 6 1441283 6 1441288 18 1441297 6 1441301 6 1441303 6 1441310 6 1441312 1 1441327 7 1441333 5 1441334 5 1441337 4 1441342 6 1441344 6 1441350 5 1441363 4 1441367 5 1441368 3 1441369 6 1441372 6 1441375 6 1441379 8 1441382 6 1441383 9 1441389 3 1441402 5 1441412 6 1441419 5 1441420 6 1441424 7 1441431 6 1441445 5 1441446 5 1441448 2 1441450 4 1441458 4 1441459 6 1441462 2 1441463 9 1441465 6 1441468 4 1441470 4 1441479 4 1441480 4 1441482 2 1441483 6 1441484 3 1441485 5 1441488 5 1441489 3 1441490 4 1441491 2 1441493 2 1441854 6 1441874 6 1441877 13 1441907 5 1441999 7 1442076 5 1442357 4 1442375 6 1442511 3 1443242 6 1443577 1 1443983 2 1444502 6 1445059 2 1445732 3 1448490 6 1450618 8 1451492 6 1451874 4 1452911 2 1453009 3 1458221 1 1459260 6 1459516 4 1465884 7 1479956 5 1517777 4 1532174 6   Zip file contains solutions files for both runs as well as logfiles. ... View more

Sorry about that. Was playing with different ideas with the ObjectiveCut and did not put it back.   You get all 184 if you run just the build solve?   I don't change anything just comment out the distance solve. ... View more

Code and data attached. ... View more

The 36 are in the 176, so it was higher for the 176. It's not so much that I do not like the answer as I do not understand why it is changing.   If I minimize the number of facilities, and it drops down to 36....why is it doing it in such a way as to pick sites so far away from the facility?   Clearly my current set of constraints would let it do it with 36 facilities....without adding any other constraints why would it not just minimize the distance between those facilities and sites. Adding in the other facilities certainly reduces the distance, but it has re-inflated the cost.  ... View more

Thanks!    Now that I got the results out, it appears to be doing the same thing my code was. The initial "build" solve puts me at 36 facilities, connected to sites that are really far away (in almost all cases it prefers things far away).  Then if I add in the code that would minimize distance, it explodes the facilities up to 176 (but now the sites are much closer).   Feel like I have to be missing something simple here.... ... View more

That, I believe, is what I am trying to do in my code. I tend to use optmodel to setup the problem and then call a solver seperately (in this case optmilp). I was using primalin, but it did not seem to do what I expected.   I changed my code to do the solving in OPTMODEL, and from the looks of the output with PRINT it appears to be doing what I was hoping. I seem to be a create data idiot, as I can't seem to get the RDC value, ZIP3 value and the FLOW between those.   This seems to get the pairs out: create data green_rdc_sol from [i j]={i in RDC, j in ZIP3: Flow[i,j].sol > 0.5}; But struggling how to get the value in Flow[i,j].sol out too.   My follow on question would be if I wanted to do this primary/secondary approach and call proc optmilp outside of optmodel do you have any guidance or examples? I seem to be much better dealing with the output data from there. ... View more