[Cbc-tickets] [COIN-OR Branch-and-Cut MIP Solver] #156: Cbc-infeasible Cplex&GLPK-feasible

[COIN-OR Branch-and-Cut MIP Solver]

#156: Cbc-infeasible   Cplex&GLPK-feasible
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Reporter:  bartgadeyne  |      Owner:  tkr
    Type:  defect       |     Status:  new
Priority:  major        |  Component:  Cbc
 Version:  2.8.8        |   Keywords:  infeasible
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 Hello all,

 I’m having issues solving my model with Cbc. Attached you can find the
 mps.
 GLPK and Cplex find feasible solutions. Cplex finds the optimal solution
 within a minute, while GLPK needs several hours to find a decent solution.

 Cbc results:

 Continuous objective value is 122787 - 0.61 seconds
 Cgl0003I 7 fixed, 0 tightened bounds, 321 strengthened rows, 0
 substitutions
 Cgl0000I Cut generators found to be infeasible! (or unbounded)
 Pre-processing says infeasible or unbounded

 When setting the parameters presolve and preprocess to off, Cbc
 (sometimes) finds an optimal solution with objective value 480069.
 However, the solution provided by Cplex is 300274.

 Do you know why cbc fails to solve this problem to optimality?

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Ticket URL: <https://projects.coin-or.org/Cbc/ticket/156>
COIN-OR Branch-and-Cut MIP Solver <http://projects.coin-or.org/Cbc>
An LP-based branch-and-cut MIP solver.