19.1 (A) An automated manufacturing system consists of four machining centers of two different types (two stations), each with two servers. It is dedicated to the production of three parts (A, B, and C) that are used in a certain assembled product made by the company. The product consists of two units of part A for every one unit of parts B and C. In addition, there is a load/ unload station with one server and a linear pallet system that is the transport station with a single shuttle cart. There is no central part storage. Parts are unloaded at machining centers, all of which are equipped with automatic pallet shuttles (APCs) that can hold one extra work part while processing of the previous part is completed. Machining cycle times are listed in the table below. At the load/unload station, time to load and clamp a part unto a pallet fixture is listed to the left of the slash and the unload time is to the right. Mean part transport time is 1.0 min. Move time empty is 0.5 min. For every transport move, there is an empty move. The parts are transported on pallet fixtures from the load/unload station directly to the machine tool APC to wait for processing. When processing is finished, parts are transferred to the unload position of the APC to await transport back to the load/unload station. Determine (a) bottleneck station, (b) total hourly output of the system, (c) production rate of each product, (d) utilization of each server, and (@) average utilization of the processing stations in the FMS. A B P Stations Part Style (1) Operation Servers ToA Tot TOB (min) (min) (min) 15 24 HMC 2 33 VMC 31 3 (n + 1) Load/unload 8/4 6/3 4(n + 2) Transport 1/0.5 1/0.5 Key: HMC - horizontal machining center, VMC - vertical machining center 7/4 1/0.5 19.1 (A) An automated manufacturing system consists of four machining centers of two different types (two stations), each with two servers. It is dedicated to the production of three parts (A, B, and C) that are used in a certain assembled product made by the company. The product consists of two units of part A for every one unit of parts B and C. In addition, there is a load/ unload station with one server and a linear pallet system that is the transport station with a single shuttle cart. There is no central part storage. Parts are unloaded at machining centers, all of which are equipped with automatic pallet shuttles (APCs) that can hold one extra work part while processing of the previous part is completed. Machining cycle times are listed in the table below. At the load/unload station, time to load and clamp a part unto a pallet fixture is listed to the left of the slash and the unload time is to the right. Mean part transport time is 1.0 min. Move time empty is 0.5 min. For every transport move, there is an empty move. The parts are transported on pallet fixtures from the load/unload station directly to the machine tool APC to wait for processing. When processing is finished, parts are transferred to the unload position of the APC to await transport back to the load/unload station. Determine (a) bottleneck station, (b) total hourly output of the system, (c) production rate of each product, (d) utilization of each server, and (@) average utilization of the processing stations in the FMS. A B P Stations Part Style (1) Operation Servers ToA Tot TOB (min) (min) (min) 15 24 HMC 2 33 VMC 31 3 (n + 1) Load/unload 8/4 6/3 4(n + 2) Transport 1/0.5 1/0.5 Key: HMC - horizontal machining center, VMC - vertical machining center 7/4 1/0.5
