where the objective function (5.3) is the average travel time of a picker, while inequality (5.4) states that the number of storage locations is at least equal to m....
Problem (5.3)–(5.6) can be easily solved in the following way. The integrity constraints on the variables nx and ny and constraint (5.6) are relaxed. Hence, inequality (5.4) will be satisfied at the optimum for the relaxed problem as an equality: