“…In fact, there are two sources of inaccessible demand: one is demand lost due to insufficient coverage and the other is demand lost due to congested facility (Abouee-Mehrizi et al, 2011;. For the first source, demand is elastic with respect to cost and customers are usually assigned to the closest facilities to maximize system total demand (Berman and Drezner, 2006;Davari et al, 2016;Marianov, 2003;Zhang et al, 2010). For the second source, customers could be denied to access the service (i.e., occurrence of balking) upon their arrival, due to capable space.…”