Modelling, optimisation and control of series supply chains and production processes

In recent years supply chains have gained the attention of both academia and industry. In this thesis, a novel state-space model of a multi-node supply chain is presented, controlled via local proportional inventory-replenishment policies. The model is driven by a stochastic sequence representing customer demand. The model is analysed under stationarity conditions, guaranteed to arise if the control parameters lie in a certain range which is identified and a simple recursive scheme is further developed for updating the covariance matrix of the system in closed form, i. e., as an explicit function of the control parameters. This allows us to analyse the effect of inventory policies on the "bullwhip effect" (demand amplification) for chains with an arbitrary number of nodes. The three-node model is subsequently analysed in detail under information sharing and the optimal policy is derived, which minimises inventory fluctuations (and inventory mean) under a probabilistic constraint related to downstream demand. It is shown that this policy can never lead to demand amplification in the chain, as long as the gain parameter of the downstream node lies in the stability region. Finally, issues related to estimation schemes based on local historical data are discussed. The main results and conclusions are illustrated via numerous examples and simulations. An alternative model of the supply chain is also developed using timed Hierarchical Coloured Petri Nets (HCPN). This approach considers supply chains as event-driven systems and studies decentralised control structures by analysing the impact of various continuous inventory policies and known forecasting methods followed by supply chain participants. CPN-Tools [fCPN] are used for the design of decision-making policies and simulation results are presented to highlight the main issues arising in real systems and to provide insights for future modelling and simulation work. Finally, a detailed case study is undertaken, for the production line of the "Bridngorth Aluminium Ltd" company which produces high quality rolled aluminium lithographic strips. An efficient representation for such production processes is provided and subsequently used for an extensive analysis and performance evaluation through appropriate metrics. In particular, the work addresses the implementation of an overall model in a simulation environment, capable of integrating the various aspects of the specific production management processes

Simulating urban soil carbon decomposition using local weather input from a surface model

Non peer reviewe

Muon (g-2) Technical Design Report

The Muon (g-2) Experiment, E989 at Fermilab, will measure the muon anomalous magnetic moment a factor-of-four more precisely than was done in E821 at the Brookhaven National Laboratory AGS. The E821 result appears to be greater than the Standard-Model prediction by more than three standard deviations. When combined with expected improvement in the Standard-Model hadronic contributions, E989 should be able to determine definitively whether or not the E821 result is evidence for physics beyond the Standard Model. After a review of the physics motivation and the basic technique, which will use the muon storage ring built at BNL and now relocated to Fermilab, the design of the new experiment is presented. This document was created in partial fulfillment of the requirements necessary to obtain DOE CD-2/3 approval