MIPLIB – the Mixed Integer Programming LIBrary

In response to the needs of researchers for access to real-world mixed integer programs a group of researchers Robert E. Bixby, E.A. Boyd, and R.R. Indovina created in 1992 the MIPLIB, an electronically available library of both pure and mixed integer programs. This was updated in 1996 by Robert E. Bixby, Sebastian Ceria, Cassandra M. McZeal, and Martin W.P. Savelsbergh. The library was updated again in 2003 by Alexander Martin, Tobias Achterberg, and Thorsten Koch, and in 2010 by a larger initiative from academia and industry.

Since its introduction, MIPLIB has become a standard test set used to compare the performance of mixed integer optimizers. Its availability has provided an important stimulus for researchers in this very active area.

Compiling MIPLIB 2017

Six years have passed since the last update in 2010. Again, the progress in state-of-the-art optimizers and improvements in computing machinery have made several instances too easy to be of further interest. New challenges are needed!

MIPLIB 2017 is a collaborative effort by Arizona State University, COIN-OR, CPLEX, FICO, Gurobi, MathWorks, MIPCL, MOSEK, NuOPT, SAS, and Zuse Institute Berlin. To continue the diversity and quality standards of the previous editions, we are looking for interesting and challenging (mixed-)integer linear problems from all fields of Operations Research and Combinatorial Optimization, ideally ones which have been built to model real-world problems.

For the first time, we will also collect model files and supplementary data and make them available in addition to the raw instance format. Though this is an optional add-on, we highly encourage model submissions in order to provide researchers with richer information on the instances. Besides high-level models, another interesting meta information could be block structure of the constraint matrix that is exploited by decomposition frameworks such as DIP or GCG. This could be specified, e.g., in dec format.

The submission for MIPLIB 2017 has been closed. We want to thank all submitters for taking the time to contribute their instances. We are currently in the process of cleaning up and analyzing the submissions.

MIPLIB 2010 – the Mixed Integer Programming LIBrary version 5

The current version of the MIPLIB was the first release assembled by a large group from academia and from industry, all of whom work in integer programming. There was mutual consent that the concept of the library had to be expanded in order to fulfill the needs of the community. MIPLIB 2010 comprises 361 instances sorted into several groups. This includes the main benchmark test set of 87 instances, which are all solvable by today's codes, and also the challenge test set with 164 instances, many of which are currently unsolved. For the first time, we include scripts to run automated tests in a predefined way. Further, there is a solution checker to test the accuracy of provided solutions using exact arithmetic.

The people involved in the creation of MIPLIB 2010 are: Thorsten Koch, Tobias Achterberg, Erling Andersen, Oliver Bastert, Timo Berthold, Robert E. Bixby, Emilie Danna, Gerald Gamrath, Ambros M. Gleixner, Stefan Heinz, Andrea Lodi, Hans Mittelmann, Ted Ralphs, Domenico Salvagnin, Daniel E. Steffy, and Kati Wolter.

A reference to this library (in bibtex format), can be found here: KochEtAl2011

Detailed information


Download

With MIPLIB test script (recommended): Without MIPLIB test script:
Older versions of the scripts can be found here, unchanged release versions of the instances that were corrected after the release can be found here. Moreover, a solution file containing all known optimal objective values of the problems can be accessed here.

Solvability of the instances

MIPLIB 2010: number of instances classified as easy, hard, and not solved

Number of solved MIPLIB 2010 instances that currently classify as easy, hard, and not solved.
'Easy' means that the instance could be solved within one hour using a commercial MIP-solver, 'hard' stands for instances, that were solved, but not in the previous conditions.

Keeping it up-to-date

The current maintainers of MIPLIB are Gerald Gamrath (gamrathKlammeraffezib.de), Thorsten Koch (kochKlammeraffezib.de), and Daniel Rehfeldt (rehfeldtKlammeraffezib.de).

News

(a complete and more detailed changelog can be found here)

Aug 2018 First feasible solution found for f2000.
July 2018 ns1778858 and ns903616 moved from open to easy, atm20-100 moved from hard to easy.
May 2018 neos-937815 moved from open to easy.
Apr 2018 satellites3-40-fs moved from hard to easy.
Mar 2018 ger50_17_trans moved from open to hard.
Sep 2017 gmut-75-50 and gmut-77-40 moved from open to hard.
Jul 2017 germanrr and ns1663818 moved from hard to easy.
Feb 2017 version 1.1.3 of the script released: fixed issue in Xpress script.
Dec 2016 pigeon-19 solved, moved from open to easy; pigeon-12, pigeon-13, and rail02 solved in less than an hour, moved from hard to easy.
Nov 2016 sct32 and usAbbrv-8-25_70 solved, moved from open to hard, ns1696083 and seymour solved in less than an hour, moved from hard to easy.
Dec 2015 rmine10 and triptim2 solved, moved from open to hard.
Nov 2015 version 1.1.2 of the script released: fixed issue in Gurobi script, print more information on environment.
Nov 2015 triptim3 solved, moved from open to easy.
Nov 2015 lotsize, opm2-z10-s2 and opm2-z11-s8 moved from hard to easy.
Aug 2015 reblock420 and rococoC11-011100 moved from hard to easy.
Jul 2015 version 1.1.1 of the script released: fixed benchmark solution file.
Jul 2015 a1c1s1 moved from hard to easy.
Jul 2015 version 1.1.0 of the script released: added capability to test on (automatically) permuted instances, fixed issue in Xpress script.
Jun 2015 eilA101-2 and rmatr200-p5 moved from hard to easy.
Jan 2015 ns2122603, neos-1140050, neos-984165, set3-10, and set3-20 solved, moved from open to hard.
Dec 2014 version 1.0.5 of the script released: fixed issue in Xpress script.
Jun 2014 ivu52 solved, moved from open to hard.
May 2014 version 1.0.4 of the script released: fixed issue in solution check for Gurobi 5.6.3 and higher
May 2014 ns1663818 solved, moved from open to hard.
May 2014 berlin_5_8_0 moved from hard to easy.
May 2014 vpphard2 moved from hard to easy.
Mar 2014 dolom1 solved, moved from open to hard.
Jan 2014 n3-3 solved, moved from open to hard.
Jan 2014 n9-3 and leo2 moved from hard to easy.
Dec 2013 in solved, moved from open to hard.
Sep 2013 janos-us-DDM solved, moved from open to hard.
Jun 2013 tw-myciel4, ns1111636, and germanrr solved, moved from open to hard.
May 2013 go19 and toll-like moved from hard to easy.
Mar 2013 queens-30 moved from open to hard.
Mar 2013 Infeasibility of neos-807456 proven, moved from open to hard.
Jan 2013 bg512142 solved, moved from open to hard.
Nov 2012 shs1023 solved, moved from open to hard.
Nov 2012 rail03 solved, moved from open to hard.
Okt 2012 pigeon-13 solved, moved from open to hard.
Aug 2012 bnatt400 moved from hard to easy.
Aug 2012 germany50-DBM solved, moved from open to hard.
Jul 2012 set3-15 and dc1c solved, moved from open to hard.
Jun 2012 hanoi5 and dg012142 solved, moved from open to hard.
Jun 2012 Solution files added for easy and hard instances.
May 2012 g200x740i, p100x588b, ns1696083, vpphard2, uc-case3, and berlin_5_8_0 solved, moved from open to hard, maxgasflow and uct-subprob moved from hard to easy
Apr 2012 neos-631710 solved, moved from open to easy, blp-ic97 moved from hard to easy
Mar 2012 r80x800 solved, moved from open to hard.
Mar 2012 First feasible solution found for ns1663818, infeasibility of lrsa120 proven, moved from open to hard.
Feb 2012 First feasible solution found for in.
Feb 2012 Added information about the feasibility of instances and new lists of feasible instances, infeasible instances, and instances with unknown feasibility.
Feb 2012 buildingenergy solved, moved from open to easy, toll-like solved, moved from open to hard
Jan 2012 11 open instances solved, b2c1s1, maxgasflow, opm2-z10-s2, opm2-z11-s8, opm2-z12-s14, opm2-z12-s7, rmatr200-p10, satellites3-40-fs, satellites3-40, and wnq-n100-mw99-14 moved to hard; transportmoment moved to easy.
Jan 2012 corrected some instances to comply with the mps-format, version 1.0.3 of the script released: added support for lp_solve and GLPK
Aug 2011 seymour-disj-10 solved, moved from open to hard
Jul 2011 Change of solution statuses: 6 instanced moved from hard to easy
Jul 2011 d10200 and rococoC11-011100 solved, moved from open to hard
Jun 2011 Change of solution statuses: blp-ic97 and atm20-100 moved from open to hard, 11 instances moved from hard to easy.
Jun 2011 ns2122603 turned out to be feasible, removed from infeasible test set.
Jun 2011 Version 1.0.2 of MIPLIB 2010 scripts released: adapted for Gurobi 4.5.0 and higher
May 2011 Version 1.0.1 of the script released: added compare result scripts which can be called via the Makefile, e.g., make cmpres SOLVER="*" TEST=benchmark.
May 2011 MIPLIB 2010 final version released.
Feb 2011 MIPLIB 2010 beta version released.
Oct 2010 Submission closed.
Mar 2010 Call for submissions.

Older versions of MIPLIB and related links

Disclaimer

Most of the data files on this site have been converted, some optimal solutions are gathered from papers and some data was typed in by hand or generated by automatic solution extraction programs. While we took every effort to make no mistakes, we can not guarantee that everything is correct. If you find any errors or have doubts about a solution, please contact us.


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Last Update July 31, 2019 by Gerald Gamrath
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