BaPCod is a prototype code that solves Mixed Integer Programs (MIP) by application reformulation techniques such as Dantzig-Wolfe or Benders decomposition. The reformulated problem is solved using a branch-and-price-and-cut (column and row generation) algorithm. The specificity of this prototype is to offer a “black-box” implementation of the method:

1. the input is the set of constraints and variables of the MIP in its natural/ compact formulation;
2. the user specifies which of these constraints and variables define the subsystems on which the decomposition is based (it is handy to test different decompositions);
3. the reformulation is automatically generated by the code, without any input from the user to define master columns, their reduced cost, pricing/separation problem, or Lagrangian bound;
4. a default column generation procedure is implemented that relies on an underlying MIP solver to handle master and subproblem but the user can upload a specific subproblem solver;
5. a branching scheme that preserves the pricing problem structure is offered by default; it runs based on priorities and directives specified by the user on the original variables;
6. default primal heuristics and preprocessing features are under developments.

Current Developers

• Issam Tahiri (Research Engineer at the IMB)
• Ruslan Sadykov (Research Fellow, Inria-Bordeaux)
• François Vanderbeck (Professor at the IMB)

Beta users

The software can be made available on special request, primarily for research purposes. It is currently in use for research purposes at:

National:

• The University Bordeaux 1,
• Inria Bordeaux Sud-Ouest,
• Université du Havre (Cédric Joncour, Sophie Michel Loyal)
• LIRMM, Université de Montpellier (Michael Poss)

International:

• University of Brescia, it, (Nicola Bianchessi)
• PUC, Rio (Marcus Poggi)
• UFF, Brasil (Artur Pessoa, Eduardo Uchoa)