Visit stops in 1st time window 1st then then orders in 2nd time window

[PredatorXix]

Hi

I am writing the algorithm in C#.

I am having an issue with the routing solver regarding the order of the stops a vehicle must visit, I have stops split into two different time windows. the orders that should be visited 1st are in a time window [0,59] and the second set of orders overlap the first set in time window [39,105].

I need to know how I can achieve that the orders in time window [0,59] are tried to be visited first.

long penalty = 1000;
for (int i = 1; i < num_nodes; ++i)
{
    if (stoplist[i].StopOrder == 1)
    {
        penalty = 1;
    }
    else if (stoplist[i].StopOrder == 2)
    {
        penalty = 0;
    }

    routing.AddDisjunction(new long[] { manager.NodeToIndex(i) }, penalty);
}

Setting the max cardinality where the stop order equals 1 gets visited but the others are dropped in the time window [39,105].

[sschnug]

Enforcing it as hard-constraint is probably the easier one:

• Define your "P"artially "O"rdered "Set" (Poset)
• Add precedence-constraints in-between those antichains -> aka for each order F in FIRST; for each order S in SECOND: F precedes S

Enforcing it through an objective / soft is imho not that easy in the routing-solver as objective-structures are kind of fixed (opposed to the CP-solver mechanism in the hard-constraint parts) with good reasons: internal invariants.

There might be some "hacky" way of introducing VERY COSTLY transition-costs between those antichains reversed (arc from order in group SECOND -> order in group FIRST = EXPENSIVE!; then one would also add DEPOT -> SECOND = EXPENSIVE).

Those are some quick ideas. The former approach is linked to many official examples. Search for the term "precedence" in the repo.

[PredatorXix]

Thank you will close this for now as gave the suggestion to my superiors.