does anyone know how to save solution time, and if there is a method
to relax a problem for XPRESS?
Our instructor gave us a project on site construction and
transportation cost minimization that takes quite long time to solve
(15 min). The problem is to reduce this time and a was wondering if we
could just first relax the integer constraints and then just add them
back for the variables that were real in the solution.
Does anyone know if this makes sense?

Thank you a lot!

Best regards,
LaGuerrière