LocalSolver

We used a LocalSolver-based solution to solve ultra-large instances posed by Google for the final round of its Challenge. Indeed, some instances induce more than 100 million decision variables and billions of expressions! Unfortunately, we do not have a sufficient amount of RAM to deal with such instances at now. So we propose a solution based on LocalSolver, easy to understand and fast to implement. This solution technique is well known by practitioners: you explore a very-large scale neighborhood by using LocalSolver, as subproblem solver. Such solution was implemented in 1 day of work.

Below are given our results. "LS direct" means that LocalSolver is used directly, by handling the whole problem. "LS based" means that LocalSolver is used to explore large neighbohoords, as described above. The results for "LS based" are obtained with a time limit of 300 seconds on a standard computer (CPU 1.73 GHz, RAM 4 GB), while the ones for "LS direct" are obtained within 1 hour on a computer with 40 GB RAM. Please have a look to http://www.localsolver.com/news.htm... or http://www.localsolver.com/news.htm... for details on how using LocalSolver to solve directly this problem.

```instances   machines   processes   decisions      LS 2.0 direct       LS 2.0 based
B1               100        5000         .5M      4,443,248,534      3,997,678,428
B2               100        5000         .5M      1,368,865,436      1,163,729,413
B3               100       20000          2M        351,813,894        266,280,383
B4              1000       10000         10M      5,796,304,487      4,682,013,089
B5               100       40000          4M      1,048,102,941      1,015,121,228
B6               200       40000          8M      9,537,599,318      9,550,921,033
B7              4000       40000        160M       RAM exploded     16,340,742,734
B8               100       50000          5M      1,323,157,749      1,316,777,967
B9              1000       50000         50M       RAM exploded     15,959,363,471
B10             5000       50000        250M       RAM exploded     19,314,990,649```

Note that these results were obtained with LocalSolver 2.0. We hope to do better with the next 2.1 planned for the end of June!

Other news

2018

LocalSolver is hiring a Numerical Optimization Engineer // 23 Jun 2018

Passionate about numerical optimization? Join a small, fast-growing tech company which is changing the game in the world of optimization.

LocalSolver is hiring a Full-Stack Developer // 30 May 2018

Passionate about computer programming? Join a small, fast-growing tech company which is changing the game in the world of optimization.

LocalSolver selected as finalist at Les PROS de la RO // 28 Mar 2018

We are glad to be selected as finalist of the French Operations Research Society competition for the best OR project in industry.

2017

New release: LocalSolver 7.5 // 20 Nov 2017

We are pleased to announce the release of LocalSolver 7.5, which comes with big novelties. Try it for free now!

Interested in doing an internship at LocalSolver? // 04 Oct 2017

Are you passionate about Operations Research and Mathematical Optimization? Have a look to our internship offers for the year 2018. Then join us!

LocalSolver sponsors OR2017 in Berlin // 31 Aug 2017

The team will be at the conference OR2017 in Berlin, September 6-8. Come to meet us on our booth, to discover LocalSolver 7.0 new features and applications.

New release: LocalSolver 7.0 // 02 May 2017

LocalSolver 7.0 offers new features and performance improvements for a bunch of combinatorial and numerical problems. Try it for free now!

2016

Welcome to our new clients // 31 Oct 2016

Several organizations have recently chosen LocalSolver to solve their most challenging optimization problems. Discover companies and institutions who trust us.

New release: LocalSolver 6.5 // 29 Jul 2016

LocalSolver 6.5 offers big performance improvements for routing & scheduling problems, as well as for almost-linear problems. Check it out for free now!

Solving a problem with 8 million boolean decisions // 15 Jun 2016

This is the number of binary decisions of the supply chain optimization problem solved in minutes by Pasco Shikishima and Future Architect, using LocalSolver.

We search for a business developer // 16 Mar 2016

Interested in selling mathematical software? Interested in joining a fast-growing tech company? Have a look to this open position at Innovation 24 & LocalSolver.

Welcome to our new clients // 01 Mar 2016

Several organizations have recently chosen LocalSolver to solve their most challenging optimization problems. Discover companies and institutions who trust us.

New release: LocalSolver 6.0 // 09 Feb 2016

LocalSolver 6.0 offers new unique, powerful features: solve routing & scheduling problems at hand using list variables, plug external functions easily to your optimization models, analyze efficiently why your model is infeasible, ...

LocalSolver 6.0 will be unveiled at ROADEF 2016, the annual congress of the French Operations Research Society, in Compiègne, 10-12th February 2016.

LocalSolver sponsors ORBEL // 25 Jan 2016

LocalSolver is glad to sponsor ORBEL30, the 30th annual conference of Belgian Operationnal Research Society at UCL-CORE, January 28-29, 2016.

2015

FICO Kaggle Challenge: Santa's Stolen Sleigh // 10 Dec 2015

The analytics company FICO has launched an optimization challenge on Kaggle: Santa's Stolen Sleigh. Julien Darlay, from LocalSolver R&D, proposes a simple optimization approach based on LocalSolver to solve this problem nearly optimally.

LocalSolver at PGMO DAYS 2015 // 25 Sep 2015

LocalSolver will be at PGMO DAYS 2015. Discover how LocalSolver solves a real-life network optimization problem with 14,000 nodes and 180,000 edges in minutes.

LocalSolver sponsors OR2015 in Vienna // 16 Jul 2015

LocalSolver sponsors OR2015 in Vienna. Come on our booth to meet the us and discover the big novelties released in LocalSolver 5.5 version!

LocalSolver 5.5 is released // 11 Jul 2015

Have a look to this new version which offers new modeling features, as well as performance improvements for a bunch of hard problems.

Welcome to our new clients // 03 Jul 2015

Several organizations have newly chosen LocalSolver to solve their most challenging optimization problems. Discover the corporations and institutions who trust us.

LocalSolver sponsors EURO 2015 // 30 Jun 2015

LocalSolver sponsors the biggest OR event in Europe: EURO 2015. Come on our booth to meet the us and discover the big novelties coming in LocalSolver 5.5 version!

LocalSolver at MIC 2015 // 15 Apr 2015

Julien Darlay will give a plenary talk at 11th Metaheuristics International Conference (MIC 2015) in Agadir, Morocco, from the 7 to 10th June 2015.

Applications of Optimization 2015 // 31 Mar 2015

Frédéric Gardi will give a talk at the Applications of Optimization 2015 workshop organized by the Danish Operations Research Society (DORS).

New release: LocalSolver 5.0 // 19 Jan 2015

LocalSolver 5.0 is out. Have a look to this new version which offers new modeling features, as well as performance improvements for a bunch of hard problems.

Je suis Charlie // 11 Jan 2015

We are shocked and depressed by the terrible events that occurred in recent days in France. We have a thought for the victims and their families. #JeSuisCharlie

2014

Welcome to our new clients // 20 Dec 2014

Several organizations have newly chosen LocalSolver to solve their most challenging optimization problems. Discover the corporations and institutions who trust us.

LocalSolver hires: welcome to Clément! // 10 Nov 2014

LocalSolver hires: our team is pleased to welcome Clément Pajean, graduated from ENSTA ParisTech, one of the French "Grandes Ecoles".

Plugging LocalSolver to the R language // 12 Aug 2014

Our Polish partner and reseller WLOG Solutions has developed the localsolver package for the R language.

New release: LocalSolver 4.5 // 21 Jul 2014

We invite all our users to install LocalSolver 4.5. This new version offers new modeling features, as well as performance and numerical precision improvements.

LocalSolver sponsors OR 2014 // 25 Jun 2014

LocalSolver sponsors OR 2014 in Aachen in Germany, from 2 to 5th September 2014. Come to our booth to discover LocalSolver and meet the team!

LocalSolver at EUROPT 2014 // 07 May 2014

LocalSolver will be presented at the 12th EUROPT Workshop on Advances in Continuous Optimization, July 10-12 2014, in Perpignan, France.

LocalSolver welcomes new clients // 23 Apr 2014

Several organizations have recently chosen LocalSolver as premier mathematical optimization solver: discover them!

LocalSolver at SMAI-MODE 2014 // 30 Mar 2014

The team was invited to present LocalSolver at the 2014 workshop on Mathematics for Optimization and Decision (MODE), part of the French Society for Applied and Industrial Mathematics (SMAI), March 26-28th 2014 in Rennes, France.

LocalSolver sponsors INFORMS 2014 // 14 Mar 2014

The LocalSolver team will have a booth and talk at INFORMS 2014 in Boston, Massachusetts. Come to meet us.

LocalSolver at Paris Machine Learning Meetup // 12 Mar 2014

LocalSolver team was recently invited to the Paris Machine Learning Meetup organized by Igor Caron, to talk about large-scale optimization related to machine learning.

Thierry Benoist's Habilitation // 06 Mar 2014

Thierry Benoist, member of the LocalSolver team, will defend his Habilitation Thesis on March 11th 2014 at Ecole des Mines de Nantes (France).

LocalSolver sponsors JFPC-JIAF 2014 // 01 Mar 2014

LocalSolver sponsors the French Meeting on Constraint Programming and Articficial Intelligence, from 11th to 13th June 2014 in Angers, France.

LocalSolver at ROADEF 2014 // 27 Jan 2014

LocalSolver will be at ROADEF 2014, the annual congress of the French Operations Research Society, in Bordeaux from 26th to 28th February. Come to meet the team!

LocalSolver at Workshop ORO 2013 // 03 Jan 2014

Frédéric Gardi was invited as plenary speaker to the ORO Workshop in Nantes. He spoke about his research line on "how industrializing local search-based OR software?" which leads to the genesis of LocalSolver.

2013

Merry Christmas: LocalSolver 4.0 is released! // 25 Dec 2013

We wish a Merry Christmas to all our clients and users: LocalSolver 4.0 is out! This new version allows to tackle large-scale mixed-variable non-convex optimization problems.

Frédéric Gardi's Habilitation // 25 Nov 2013

Frédéric Gardi, member of the LocalSolver team, has defended his Habilitation Thesis on November 25th 2013 at Université Pierre et Marie Curie (Paris 6, Jussieu).

Innovation 24, the parent company of LocalSolver // 17 Oct 2013

Discover Innovation 24, the parent company of LocalSolver, also offering expert services in business analytics and operations research.

LocalSolver wins on some of the hardest MIPLIB instances // 15 Oct 2013

LocalSolver wins against both Gurobi and IBM ILOG Cplex on some of the hardest MIPLIB instances. Have a look!

LocalSolver wins against MILP, MIQP, and CP solvers on QAPLIB // 01 Oct 2013

While MILP, MIQP or CP solvers are out of scope, LocalSolver reaches state-of-the-art results within 5 minutes on Quadratic Assignment Problem.

Welcome to our new clients // 24 Sep 2013

We welcome our new clients: Hitachi, MédiaTransports (Publicis), NIES, Nanjin University.

LocalSolver tutorial in IFORS Newsletter // 23 Sep 2013

IFORS is the International Federation of Operational Research Societies. A tutorial on LocalSolver appears in the last IFORS Newsletter.

Welcome to our new partners // 19 Sep 2013

We are glad to welcome new LocalSolver partners.

LocalSolver at the Summer School "Francesco Turco" 2013 // 10 Sep 2013

Our Italian partner LAC is sponsoring of Summer School "Francesco Turco" 2013. LocalSolver will be presented during the event.

LocalSolver at OR55 in Exeter (UK) // 13 Aug 2013

LocalSolver is sponsoring OR55 in Exeter (UK), 3-5th September 2013. Come to our booth to meet the team!

LocalSolver at OR 2013 in Rotterdam // 30 Jul 2013

LocalSolver is sponsoring OR 2013 in Rotterdam, 3-6th September 2013. Come to our booth to meet the team!

LocalSolver 3.1 is out // 28 Jun 2013

LocalSolver 3.1 is now available. Enjoy it!

LocalSolver at EURO-INFORMS 2013 // 15 Jun 2013

LocalSolver sponsors EURO-INFORMS 2013 in Rome. Don't miss the presentations made by the team!

Speed dating with LocalSolver // 06 Jun 2013

A nice post about LocalSolver by the OR blogger Marc-André Carle.

LocalSolver at ECCO 2013 // 30 Apr 2013

Don't miss the presentation of LocalSolver at ECCO 2013 in Paris.

Welcome to our new clients // 02 Apr 2013

We welcome our new clients: Air Liquide, Armée de Terre, Fujitsu.

2012

Customers & Partners // 14 Nov 2012

Welcome to our new customers & partners!

LocalSolver in Japanese // 08 Oct 2012

LocalSolver now speaks Japanese thanks to our partner MSI.

Logistics & Automation Consulting chooses LocalSolver // 24 Sep 2012

The Italian company Logistics & Automation Consulting (LAC) chooses LocalSolver as mathematical programming partner.

LocalSolver now in OR education // 10 Sep 2012

LocalSolver appears as complement of classical MIP and CP solvers in OR courses in French universities and high schools.

LocalSolver at ISMP 2012 // 15 Aug 2012

LocalSolver was at ISMP 2012, the world congress in mathematical programming, held in Berlin. Here are the (provocative!) slides.

Customers & Partners // 02 Aug 2012

Welcome to our new customers & partners!

New release: LocalSolver 2.1 // 06 Jul 2012

LocalSolver 2.1 was released the 6th July 2012. All users of LocalSolver 2.0 can take advantage of this new version for free.

LocalSolver at EURO 2012 // 27 Jun 2012

LocalSolver is a sponsor of EURO 2012 in Vilnius (8-11 July). Come on exhibition booth #20 to discover LocalSolver and the team!

We have submitted a LocalSolver-based solution for the final round of Google ROADEF Challenge. Here are given our results.

LocalSolver in Optimization Days 2012 // 04 May 2012

LocalSolver was presented in Optimization Days 2012 in Montreal. You can download the slides of the presentation.

Frédéric Gardi wins the 2012 Robert Faure Prize // 16 Apr 2012

This prize is awarded every 3 years by the French OR society to a worthy young researcher. This is the first time it has been awarded to an engineer working in industry and not to an academic.

LocalSolver at ROADEF 2012 // 08 Apr 2012

LocalSolver sponsorizes ROADEF 2012 congress. LocalSolver 2.0 will be presented in industrial semi-plenary session. Come to discover it!

LocalSolver available on Mac // 26 Mar 2012

Good news for Apple fans: LocalSolver is now available on Mac.

Official launch of LocalSolver 2.0 at Bouygues Headquarters // 11 Mar 2012

LocalSolver team invites you to the official launch of the commercial version of its new-generation solver: Tuesday March 13 2012.

LocalSolver tackles B instances on Google ROADEF Challenge // 24 Feb 2012

LocalSolver is able to solve some of the ultra-large instances from set B. Here are given some results.

Ranked 25th among 82 teams from 33 countries, LocalSolver is the sole math programming solver qualified for the final round.

LocalSolver at Aussois 2012 // 09 Jan 2012

LocalSolver was recently presented at 16th Aussois Combinatorial Optimization Workshop.

2011

LocalSolver in 4OR journal // 01 Sep 2011

The first paper on LocalSolver has been published in 4OR, a Quarterly Journal of Operations Research published by Springer.