“…Type Reference Order Picking Systems Picker-to-Parts [18], [19], [20], [21], [22], [23], [24], [25], [26], [27], [28], [29], [30], [31], [32], [33], [34], [35], [36], [37], [38], [39] Parts-to-Picker [40], [41], [42], [43] Operative Planning Issues…”