Executing the nurses project (1)

Describes how to observe infeasibility, conflicts and proposed relaxations.

The nurse scheduling project has been designed with infeasible data. The IDE lets you know when a project is infeasible, proposes relaxations, and displays conflicts to help you make it feasible. In this section, you are going to execute the model and observe infeasibility.

Double-click on the settings file, nurses.ops, to open it in the editing area.
In the displayed settings file, select Language > Run in the tree structure in the left panel and make sure that the Display relaxations and Display conflicts options are checked.

These options, which are turned on by default, tell the IDE to compute and display suggested relaxations and conflicts, when they exist, in the Conflicts and Relaxations tabs.

Figure 1. Relaxations and conflicts checked by default
Right-click on the nurses project and select Run>Basic configuration.
After a few seconds, the Conflicts and Relaxations tabs indicate where the relaxations and conflicts are, as shown in the following screen captures.

When a conflict or relaxation is selected in either the Conflicts or Relaxations tabs, the corresponding code is highlighted in the model.

Figure 2. Displaying conflicts for nurses.mod

Figure 3. Displaying relaxations for nurses.mod

When you get such messages after execution of a model, the next step consists in Studying the suggested relaxation.