Analysing the performance of an automated pathology specimen handling system

This paper determines the performance of a pathology specimen handling system currently under development that performs two fundamental functions, sample tube sorting and sample tube aliquoting. In order to do this a novel capacity model and a simulation model have been developed to analyse the performance of the machine. A capacity model and a simulation model are necessary in order to measure the efficiency of the conveyor system as a means of transferring pucks and tubes between modules as each is insufficient on its own. Furthermore strategies for controlling the machine and eliminating deadlocks are also developed in order to optimise the machine performance and to make it robust. From numerical investigations the best number of pucks and the best puck queue sizes are determined in order to maximise throughput. The results show that a complex relationship exists between the number of pucks, the puck queue sizes and the primary tube arrivals and keeping these components in balance is essential in maintaining system performance.