“…An efficient solution needs to consider constraints that can impact execution costs or increase problem complexity. Such constraints may include relocatable tasks ( [15,16]), deadline ([14, 12, 17, 18]), environment's uncertainties ( [19,17]) and different robots' properties such as load capacity ( [9,12]), traffic speed ( [11,16]) and energy consumption ( [13,14,12]). In smart warehouses, constraints still include the dispersion of robots, location and demand of the tasks, number of delivery stations, warehouse layout, and other environmental features such as obstacles, roadblocks, and other unpredictable situations.…”