Manage Optimization Constraints

Constraints in an optimization scenario are defined and managed in the Constraints tab.  Constraints that have been created will appear in the list of constraints.  This document explains how to create new constraints and manage existing ones in this tab.

 

Add Constraint - This box allows you to select a type of constraint to add to the optimization scenario.  The different types available are described here: https://support.lityxiq.com/524228-Types-of-Optimization-Constraints.  Once you select the type you wish to add, click the Add Constraint button.  You will then be taken to the Edit Constraint dialog, which is explained here: https://support.lityxiq.com/026974-Edit-Constraint---Basic-Setup.

Constraint List - The list of constraints shows all constraints currently defined for the scenario.  Active constraints are shown with a green bar to the left, while inactive ones are shown with a red bar.  The text shown gives you an overview of the constraint including the label it was given and the metric and basis involved.  Constraints can be re-ordered using drag and drop.  The ordering of constraints does not matter when it comes to how they are interpreted, but you may want to see more important constraints at the top of the list.

These activity buttons can be used for each constraint.  In order, the functionality the provide are:

  • Edit - click to edit the constraint definition.  The starting point for editing a constraint is described more fully here: https://support.lityxiq.com/026974-Edit-Constraint---Basic-Setup.
  • Inactivate/Activate - if the constraint is currently active, this will inactivate it.  Otherwise, it will activate an inactive constraint.  Activating and inactivating can also be accomplished within the Edit Constraint dialog.  Note that an inactive constraint will be ignored when the scenario is executed.
  • Delete - click to remove the constraint from the scenario.

Identify Infeasibilities - This box is only available with the Gurobi-enhanced LityxIQ license.  Check this box to try to identify which constraints are causing infeasibility, in the case where the problem cannot be solved due to infeasibility issues. Note that this can add significant execution time for large problems that have an infeasibility.