MIP solver does not use initial solution

AIMMS Knowledge Base Article - KB00011

MIP solver does not use initial solution

Summary

You can initialize the solution of a MIP when solving it with CPLEX, GUROBI or CBC.

Symptoms

You have an initial solution, but the solver does not seem to use it.

Cause

There are several causes for this problem:

  • The solver you use does not support the use of an initial solution. Currently only CPLEX, GUROBI and CBC support this.
  • The relevant option does not have the correct settings. 
  • You didn’t assign the initial solution to the variables.

Resolution

Make sure that you use a solver that supports the use of initial solutions (CPLEX, GUROBI or CBC). You can contact AIMMS if you have doubts.

Furthermore, make sure that the following option (Settings - Project Options…) is set:

  CPLEX X.X: Specific solvers – CPLEX X.X - General - Advanced start -> Use advanced basis

  GUROBI X.X: Specific solvers – GUROBI X.X - MIP - MIP Start -> Yes

  CBC X.X: Specific solvers – CBC X.X - MIP - MIP Start -> On

Assign the values of your solution to the decision variables in your project and solve the model.

More information

For more information, please contact us at support@aimms.com.