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The presented article deals with the issue of inventory management optimization through modelling and simulation in the software Tecnomatix Plant Simulation. Based on an in-depth analysis of the supply chain with an emphasis on inventory management, a simulation model was developed. It was optimized using the inventory theory methodology in combination with a discrete-event simulation approach. Dynamic simulation made it possible to perform experiments and optimize the existing state. The solution to the problem is elaborated on a case study to achieve the efficiency of the supply process of a specific operation of a clothing retail chain, which is struggling with the problems of excessive and inaccurate supply. [ABSTRACT FROM AUTHOR]

Nowadays, stock management became a strategic decision used by organizations due to the high impact it has on the overall performance of supply chains. This paper evaluates the impact of the implementation of a R, S inventory policy in the finances of a distribution network. The research involves the functioning of a hardware supply chain conformed by a retailer and a manufacturer, which is simulated trough system dynamics. The main results of the study validate the positive impact that the policy about network liquidity have. Likewise, it is possible to determine the dominance of parameters such as demand, the review period and the maximum production capacity over the overall performance of the system. [ABSTRACT FROM AUTHOR]

Today, in our country, enterprises face big challenges from a fierce competition, not only internal, also international, which operate with better conditions than ours. It is time to take advantages from scientific, technological and computing progresses like simulation, to be included by the management of organization, known as complex and dynamic systems. The operating manager for a wood enterprise likes the possibility to abate costs. His concern about the amount of compressed board stored and pretends to spend as little as possible on the transportation from the processing plants to the sales shops. An operating policy is built towards the costs reduction, working on three linked steps: transport, assuming that there are no problems with existence; warehouse inventory where the estimated demand derives from the results of the transportation item; and the distribution-inventory, solved by drawing a simulation model which uses initial values, the results of the previous items. The model refers to using tools from Linear Programming, Inventory theory and Dynamic Simulation. The costs generated with this analysis are smaller to those obtained without control on the system, 18.23 % on average. A recurrent solving method is contributed. [ABSTRACT FROM AUTHOR]

Abstract: The dynamic behavior for a high-purity/high-conversion reactive distillation is investigated. The impact of disturbance magnitudes and directions on both open loop and closed loop stability of the system is studied. Excess of less volatile reactant in two-reactant-two-product generic reactive distillation is found to enhance open loop stability, but decreases the products purity. However, excess of more volatile reactant trigger the system to another steady-state. Open loop changes in the manipulated variables (i.e. vapor boilup from the reboiler and reflux rate from the condenser) in certain directions are found to be intolerable due to their effect on both the reaction kinetics and the fractionation capacity of the column. The performance of the open loop system is improved significantly with the inclusion of internal inventory control of one of the reactants but this has been found to be insufficient when there is a change in some inputs in certain directions. Steady-state rating analysis on the system suggests that the limitations on certain inputs could be resolved by including a single-end controller, which will act to maintain the separation capacity of the column and thus stabilizes the system. [Copyright &y& Elsevier]

In this study, the design and control of the hydration process for the production of tert-butyl alcohol (TBA) through a hybrid reactive extraction configuration was proposed. Firstly, TBA production by using a reactive distillation configuration and a hybrid reactive extraction configuration without the inert n-butene (NC4) was investigated. Due to the azeotrope between TBA and water (H 2 O), azeotropic distillation is required in the separation section with cyclohexane (CyH) as the entrainer. Compared to the reactive distillation configuration, the hybrid reactive extraction configuration was superior in terms of the total annual cost (TAC) and energy savings for the production of 99.9 mol% of TBA. Subsequently, the feed composition with the inert NC4 for a more realistic feeding condition was also investigated while using the hybrid reactive extraction configuration. The major differences in the two feed conditions were the compositions in the outlet of the reactive extraction section and the functions of the C1 column. Then, two control structures [a single-point temperature control (CS1) and a dual-point temperature control (CS2)] with three inventory control loops (inventory A–C) of the hybrid reactive extraction configuration with the inert NC4 were proposed. The simulation results revealed that both stoichiometric balance and liquid–liquid equilibrium (inventory C) in the RE column should be used for the dynamic operation. The CS2 with inventory C (CS2C) was found to be the optimal control strategy in this process. Image 1 • A hybrid reactive extraction configuration was proposed for the hydration process. • The proposed hybrid configuration saved energy and cost significantly compared to the conventional configuration. • A dual temperature control scheme could provide the fastest responses to reach steady state under disturbances. [ABSTRACT FROM AUTHOR]