I am doing outage analysis on a network using barriers points (Red Points) on the midpoints of lines generated by "Generate points along lines". Make a loop for every outage; each time a barrier is applied on a single line (equal to line outage) and solve the problem to find the minimum facilities I need for the network so that every node (14 points) has connection to at least a facility all time. Combining all results of solving location allocation problem should give me the total minimum facilities to be installed in case of line outage. However, I found that the facilities found from the solution contain some extra ones I can delete them with getting the same access to at least a facility which means it is not minimum solution. Any idea?
Note: this question is similar to one I posted recently and asked how to solve location allocation based on facility outage; here we have line outage.
Figure 1: My model to solve the problem
Figure 2: Result (Black Circle) after running the model
Ex: Without facility 10 (I deleted it because I see it extra facility)
If line 9-10 is out of service, still demeand-10 has a connection to facility-11.
If line 10-11 is out of service, still demand-10 has a connection to facility-9. and so on
As in your previous post, you have described a process that has given you an unexpected result. It is probably because the iterative process you are choosing will not give you a global solution. Perhaps what you should state is the problem you are trying to solve rather than asking why your process did not work.