VRP - Modifiable Fixed Cost

[CraigSteverango]

Hi Everyone,

In solving a routing problem, there is a fixed cost for each store included on a route.  For example, if in solving the VRP, a route has 4 stores, I would need to have a fixed cost of $800 ($200/store).  The fixed cost needs to change depending on the number of stores that are assigned to a route. 

My question relates to whether I can have the VRP solve a problem where the fixed costs can be modified depending on the number of stores on a route (to a max of 8 stores/ route).  If this is possible, how might I go about doing it?  Can I use a variable within the Fixed cost part of the routes?

Any help would be appreciated,
Craig.

[NaAn]

Hi Craig,

In your problem, is the fixed cost (cost per store visit) the same across all routes?

If the answer is yes, you do not need to model them in the routing problem. As long as all orders are assigned, the overall fixed cost stays the same. Therefore, it has no impact to the optimization.

If the fixed cost per store visit is different between routes, then the VRP solver cannot handle it right now. The �??fixed cost�?� field in Routes class represents a fixed monetary cost, such as vehicle rental cost that is incurred only if the route is used in a solution. It is not proportionally to the number of orders assigned to the route.

In addition, if you want to restrict the maximum number of orders assigned to a route, you can set this value through the MaxOrderCount field in Route Properties.

I hope this answers your question.

Thanks.

Anna