Controllable processing time policy in job shop manufacturing systems: design and evaluation by simulation modelling

Abstract

The research proposed in this paper concerns the management of job-shop manufacturing systems with machines characterised by controllable process times. The process times are controlled by the selection of cutting speed. It has been developed a multi-domain simulation environment by ExtendSim package linked to the cutting parameters' database of the tools. Two combined simulation models have been developed. The first simulation model uses the cutting tool parameters to define the relation between the cutting speed and the waiting time of the parts in queue. The output of this model is the knowledge used by the control time policy. It is controlled the waiting time of the parts in each machine; based on the information provided by the first simulation model it is selected the cutting speed of the tools, and the process time is modified. The second simulation model is used to test the proposed policy. The numerical results highlight the benefit in terms of performance measures obtained.