A study of reconfigurable manufacturing systems with computer simulation

[摘要] ENGLISH ABSTRACT: Reconfigurable Manufacturing Systems (RMSs) have the ability toreconfigure hardware and control resources at all of the functional andorganizational levels. This allows for quick adjustment of productioncapacity and functionality in response to sudden changes in marketor in regulatory requirements.This study evaluates the characteristics and operation of automatedreconfigurable assembly lines using discrete event simulation. The assemblyline uses a conveyor system which transports pallets to variousmachines to perform the assembly process. Different conveyor configurationsare developed for the same assembly process using Simiosimulation software. A part family consisting offive variants areassembled on the same assembly line with a large variation in theproduction quantities for each product. This requires the assemblysystem to be able to quickly adjust its functionality and capacity.Multi-objective optimization is performed on the models through theuse of a Pareto exhaustive search experiment. The two contradictingobjectives used are the throughput rate of the system and the averagework in progress, with the aim of maximizing the former and minimizingthe latter. From the Pareto exhaustive search experiment, aPareto front is constructed showing which configuration is preferredunder certain operation conditions. However it is concluded that thePareto front can be tailored to fit the specific needs of the decisionmaker, depending on what the decision maker is willing to pay.An experiment that evaluates the effect of changing the conveyorspeed is performed. It is established that under certain operatingconditions, increasing the conveyor speed higher than the ceiling valuewill not improve the performance of the system. A production scenario was also developed which include different ordersizes for each of the five parts of the part family. The configurationshave to alter their capacities based on the order sizes to test whichsystem performs the best under these operating conditions. For thisexperiment, the ramp-up time was of interest but the best system waschosen based on the combination of throughput rate and the averagework in progress.From the results of the different experiments, it is recommended tofirst determine the maximum capacity and the operating logic beforechoosing one of the configurations. Once this is decided, theinformation gathered from the experiments can then be tailored forthe decision maker to establish the best operating conditions for thechosen con guration. The developed simulation models are used as aDecision Support System for future research on the topic. It is recommendedfor future research to focus on using Automated Guided Vehicles(AGVs) instead of a conveyor system as transportation method.

[发布机构] Stellenbosch University