<div dir="ltr"><div class="gmail_default" style="font-family:georgia,serif;font-size:small">Hi,</div><div class="gmail_default" style="font-family:georgia,serif;font-size:small"><br></div><div class="gmail_default" style="font-family:georgia,serif;font-size:small">
I've been trying to use or-tools interface with CLP to solve assignment problems for VRP, and I found out that the solver does not respect all constraints when I use non unitary demands. Unitary demands work perfectly fine.</div>
<div class="gmail_default" style="font-family:georgia,serif;font-size:small"><br></div><div class="gmail_default" style="font-family:georgia,serif;font-size:small">To be more specific :</div><div class="gmail_default" style="font-family:georgia,serif;font-size:small">
<br></div><div class="gmail_default" style="font-family:georgia,serif;font-size:small">I choose nb_customers and nb_warehouses.</div><div class="gmail_default" style="font-family:georgia,serif;font-size:small">I generate randomly those customers and warehouses within [0,1000]², and demands in [1,10] (all integers), and capacities that make sure the problem is feasible. I then use or-tools MPSolver interface for CLP with binary variables to indicate if customer i is assigned to warehouse j, and capacity balancing constraint between depots, and in the solution returned, there are some customers that weren't assigned to any warehouse</div>
<div class="gmail_default" style="font-family:georgia,serif;font-size:small"><br></div><div class="gmail_default" style="font-family:georgia,serif;font-size:small">I work with nb_customers=2000, I'm pretty sure I'm ok with my constraint, since if I use only unitary demands, all 2000 customers are affected, but when I use random demand between 1 and 10, the problem is said to be solved to optimality, but only between 1997 and 1999 customers are affected in most cases. If we use demands in [1,100] , it gets even worse with only 1800 customers affected.</div>
<div class="gmail_default" style="font-family:georgia,serif;font-size:small"><br></div><div class="gmail_default" style="font-family:georgia,serif;font-size:small">Have someone noticed something like this ?</div><div class="gmail_default" style="font-family:georgia,serif;font-size:small">
<br></div><div class="gmail_default" style="font-family:georgia,serif;font-size:small">I can send more details and source code if you like,</div><div class="gmail_default" style="font-family:georgia,serif;font-size:small">
<br></div><div class="gmail_default" style="font-family:georgia,serif;font-size:small">Thanks in advance,</div><div class="gmail_default" style="font-family:georgia,serif;font-size:small"><br></div><div class="gmail_default" style="font-family:georgia,serif;font-size:small">
Thierry</div></div>