For MB distribution, costs C,, are as given in Table 6'8 (i = l'2'3'4' i = l'2' ' ' ' '7) ' comparing with the original who-iesaler-retailer shipping costs inTable 6.2,
there are no infeasible silpplng routes for wholesaler-retailer transportation oaule o.g). For transshipmerrtiesti"ation transportation, we introduce the fol- lowing decision variables: