MIPLIB - Mixed Integer Problem 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.

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.


More than 7 years have past since the last update of the MIPLIB. And again improvements in state-of-the-art optimizers, as well as improvements in computing machinery have made several instances too easy to be of further interest. Therefore we have purged the library of those instance and filled the free slots with more worthy candidates. As the instances also the maintainers and the host of the MIPLIB have changed.

The current maintainers are Alexander Martin <martinKlammeraffemathematik.tu-darmstadt.de>, Tobias Achterberg <achterbergKlammeraffezib.de>, Thorsten Koch <kochKlammeraffezib.de> and Gerald Gamrath <gamrathKlammeraffezib.de>.

We would be happy if you contribute to this library by sending us hard and/or real life instances.
If you have any instances you would like to add to MIPLIB or solutions to unsolved problems, please send an email to kochKlammeraffezib.de.

A reference to this library (in bibtex format), can be found here: AchterbergKochMartin2006

We request your help!

Development over the years

MIPLIB 2003: development of the number of solved instances

Comparison of the number of solved MIPLIB 2003 instances at the beginning of each year.
'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.


Apr 2010 ds and stp3d have been solved. Update of the levels of difficulty of the instances with respect to CPLEX 12.1 and Gurobi 3.0.
Apr 2009 sp97ar and timtab2 have been solved. Diagram showing the development of the solution states is now available.
Nov 2006 a1c1s1, swath, protfold, rd-rplusc-21, msc98-ip, and atlanta-ip have been solved.
Jun 2006 arki001, glass4, and roll3000 have been solved.
Jan 2006 Some updates. Images of sparsity patterns are now available.
Feb 2005 MIPLIB 2003 final version. Many updates to the website.

Related Links

MIPLIB2003 instances in AMPL input format

Hans Mittelmans MIP collection

DEIS - Operations Research Group / Library of Instances

Anureet Saxenas Benchmark Instances in .mps format

COR@L - Computational Optimization Research at Lehigh instances


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 2010/06/09 13:56:10 by Gerald Gamrath
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