Need to define a soft minimum capacity for vehicles

Hi,

I have been using Jsprit and it has panned out very nicely for me.
I have a use-case that there are vehicles which operate a certain minimum capacity (at least direction-ally we want them to function respecting minimum capacity). I was wondering if some-how we can make these vehicles carry minimum number of shipments using Jsprit. Any help in this regard would be great. Thanks.

By context it should be achievable by soft route constraint. But there is a lot undefined variables. Could you provide more specific example of what result you want to achieve?