I am having trouble formulating the following constraint:
I am looking to formulate a constraint that if a facility was opened at some point in time, then $Y[j,t]$ does always have to be $1$ from that point in time onwards (see values below). How do I do that?
Edit from comments:
It is also possible to close initially existing facilities using a closing variable $S[j,t]$. It is generally possible to close a facility, just not one that has been opened by the model using the $O[j,t]$ variable.