6. Conclusion and outlook

The use of integer linear programming and a solver such as GLPK means that optimal solutions can be found "quickly". The GLPK solver takes much less time than the human planner to build tours, which are often better. Because it is developed in VBA for Excel, the interface is easy to use for the planner. Finally, the graphical display of tours in Google Earth facilitates communication and information sharing. Simply send the .kml file (size 10 kb) to another employee, and he or she can display the tours on his or her version of Google Earth.

In a future research project, we intend to develop mathematical models to optimize the loading of linen into wardrobes prior to distribution. These cupboards have several compartments in which the linen is placed in stacks. This is a three-dimensional bin-packing problem, i.e. a problem of placing objects (the laundry) in three-dimensional...