Originally posted by: SystemAdmin
The "Switched to devex" messag just says that the automatic pricing rule decided to use devex pricing.
A shift gets introduced either to cope with numerical issues in the model or by the Harris ratio test. For primal simplex, it means that some of the right hand sides and bounds are slightly relaxed. After having produced an optimal solution to this relaxed problem, the shift must be undone. Depending on certain characteristics of the optimal solution to the relaxed problem, this undo process is sometimes performed using the dual simplex algorithm. This is the reason why you see "Dual objective" messages in your primal simplex log.
Tobias
#CPLEXOptimizers#DecisionOptimization