Ayar and Yaman (2012) use a real wo

Ayar and Yaman (2012) use a real world data set with 34 nodes and 167 services, and generate a random network of 66 nodes and 1200 arcs, and test them for 400 up to 1000 commodities, Their first conclusion is that by increasing the number of commodities, the optimality gap decreases. Moreover, adding valid inequalities and variable fixing strategies result in significant improvements both in time and solution quality. All their instances are soved to optimality within 6 min. Ayar and Yaman(2012) also investigate variable fixing based on capacity restrictions, but in overall, it does not bring much improvement to their previous valid inequalities and varable fixing strategies.