Question: An automated guided vehicle system is being proposed to deliver parts between 40 work-stations in a factory. Loads must be moved from each station about once every hour; thus, the delivery rate = 40 loads/hr. Average travel distance loaded is estimated to be 250ft and travel distance empty is estimated to be 300 ft. Vehicles move at a speed = 200 ft/min. Total handling time per delivery s 1.5 min (load = 0.75 min and unload = 0.75 min). Traffic factor Ft becomes increasingly significant as the number of vehicles ne increases; this can be modeled as:
Determine the minimum number of vehicles needed in the factory to meet the flow rate requirement. Assume A = 1.0.