MiniZinc Challenge 2011

The Challenge

The aim of the challenge is to start to compare various constraint solving technology on the same problems sets. The focus is on finite domain propagation solvers. An auxiliary aim is to build up a library of interesting problem models, which can be used to compare solvers and solving technologies.

Entrants to the challenge provide a FlatZinc solver and global constraint definitions specialized for their solver. Each solver is run on 100 MiniZinc model instances. We run the translator mzn2fzn on the MiniZinc model and instance using the provided global constraint definitions to create a FlatZinc file. The FlatZinc file is input to the provided solver. Points are awarded for solving problems, speed of solution, and goodness of solutions (for optimization problems).


  • 2011-09-12 The results of the MiniZinc Challenge 2011 are available here.
  • 2011-07-26: the deadline for final submission has been moved to 7 August 2011.
  • 2011-06-28: information about entry submission has been mailed to registered entrants.
  • 2011-05-20: the problem submission deadline has been moved to 10 June 2011.


  • Registration opens: 1 May 2011.
  • Problem submission deadline: 10 June 2011.
  • Initial submission round begins: 1 July 2011.
  • Initial submission round ends: 20 July 2011.
  • Final submissions: 7 August 2011.
  • Announcement of results at CP2011: 13 September 2011.


Entrants must register their intention to enter the contest before the first submission round.
The first submission round is an opportunity for us to provide feedback concerning your entry; it does not count towards the final result.
Feel free to register and later withdraw.

To register send an email with the following subject line

    [MZNC11] registration


    mzn-challenge 'at'

In the body of the email please include an email address at which we can contact you.


We will provide submission details via email to the address provided above.

Problem Submission

We strongly encourage all entrants to submit one or two MiniZinc models satisfying the contest requirements, together with instances for these models. They can be submitted as tarballs to:

    mzn-challenge 'at'

The sooner they are submitted the better, the deadline is 1 June 2011.


The rules for the MiniZinc Challenge 2011 are available here.
If we need to make changes to the rules, all registered entrants will be informed by email.


The judges will be responsible for selecting the tested instances, vetting the results, and ruling on any questions that arise during the competition.

  • Jimmy H.M. Lee. Chinese University of Hong Kong.
  • Barry O'Sullivan, Cork Constraint Computation Center.
  • Roland Yap, National University of Singapore.


This is the third time this challenge is run, and there are many possibilities for comparing CP solvers. The rules try to make a sensible set of choices for the comparison. We would welcome any comments or suggestions regarding the running of this challenge.

We can be contacted at:

    mzn-challenge 'at'

Mailing list

The G12 users mailing list is intended for general discussion of MiniZinc and FlatZinc.
If you would like to join then send a mail with subscribe in the body to:

	g12-users-request 'at'

After subscribing you can then send mail to:

	g12-users 'at'


The G12 MiniZinc page includes a list of resources related to MiniZinc and FlatZinc.

The G12 MiniZinc Distribution includes a MiniZinc-to-FlatZinc converter and a large suite of MiniZinc examples and benchmarks.

The MiniZinc Challenge 2010 webpage, include the results from that year.

The MiniZinc Challenge 2009 webpage, include the results from that year.

The MiniZinc Challenge 2008 webpage, including the results from that year.