A carousel storage system is to be designed to serve a mechanical assembly plant. The specifications on the system are that it must have a total of 400 storage bins and a throughput of at least 125 storage and retrieval transactions per hour. Two alternative configurations are being considered: (1) a one-carousel system and (2) a two-carousel system. In either case, the width of the carousel is to be 4.0 ft and the spacing between carriers = 2.5 ft. One picker-operator will be required for the one-carousel system and two picker-operators will be required for the two-carousel system. In either system vc = 75 ft/min. For the convenience of the picker-operator, the height of the carousel will be limited to 5 bins. The standard time for a pick and deposit operation at the load/unload station = 0.4 min if one part is picked or stored per bin and 0.6 min if more than one part is picked or stored. Assume that 50% of the transactions will involve more than one component. Determine
(a) The required length of the one-carousel system and
(b) The corresponding throughput rate;
(c) The required length of the two-carousel and
(d) The corresponding throughput rate.
(e) Which system better satisfies the design specifications?