1,721,020 research outputs found
"Advanced Modelling for Multilevel Analysis in Complex Processes Involving Ship Construction"
No full textAnticipating critical events to improve the remote scheduling of coordinated production.
No full textthis paper proposes a methodology to improve the time-performance of distributed simulation based
on the HLA architecture using commercial simulators. In the context of industrial production, for instance, the
timing of information transfer among federate simulators becomes an important issue whenever production
control and scheduling are very closely linked. In such a context the re-scheduling of an existing production plan,
as determined for instance by a rush order, is usually decided upon at the control level in the hierarchy of
federates; however it cannot be communicated to the different federate plants until a status/parameter update is
instantiated and established. The study presented in this paper specifically focuses on the impact of machine
failures at the federate plant level. The random nature of the failure processes associated to the machines of the
federate production plants makes it difficult to establish when such occurrences may take place: therefore the
events driving the exchange of state variables among federates cannot be set with certainty ahead of time. This
research proposes a one-off methodology to statistically determine when critical events, such as machine
failures, are likely to occur. Based on such information it is possible to intersperse additional events among those
associated to the usual production/process milestones and thus significantly reduce delays in the transfer of
critical status parameters among federates and waste of simulated time. Applications are presented to relate these
time-performance benefits to measurable improvements in production performance
Fleet Management System Requirements for the Maritime Logistics of the Chemical Industry
No full text
Simulation-Based VV&A Methodology for HLA Federations: an Example from the Aerospace Industry
No full textThis paper establishes a methodology for the validation of a whole federation of simulation models which represent the reality of the supply chain in the context of the aerospace industry. There are many possible ways to address this problem, among these, the simplest way appears to be the analysis of the real-life situation, based on historical data. The use of historical data is not always a viable approach, due to the lack of a sufficiently extensive pool of reliable data. Therefore a simulation-based VV&A approach is often required before the operative use of models. Historical data is reproduced through a long series of runs of a simulation meta-model. The major issue associated to the validation of a federation of simulation models is that each simulation model needs to be validated as stand-alone and at the same time it needs to be validated as a member of the whole federation, or of a portion of it
Evaluation and Analysis by Simulation of a Production Line Model Built with Back-Propagation Neural Networks
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