Examinando por Materia "Inventory control - mathematical models"

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    Ítem
    Allocation of intermediate buffer storage capacities in a production line
    (2013-07-24) Vélez Gallego, Mario César; Jaramillo Jiménez, Jhull B.; Universidad EAFIT. Departamento de Ingeniería de Producción; marvelez@eafit.edu.co; jjaram61@eafit.edu.co; Gestión de Producción y Logística
    In this research proposal we consider a production line with random demand and subject to random failures at each workstation -- Every time a workstation fails, a corrective maintenance activity is triggered to repair the workstation -- In order to palliate the effect of the random failures in the performance of the system, intermediate buffers are placed in-between workstations -- An inventory holding cost that increases with the stage of the process is associated to each buffer -- The research objective in this work is to allocate capacity to each intermediate buffer in the line so that the average cost per time unit is minimized while the average service level is kept above a minimum value -- In this paper we assume that unsatisfied demand is lost and the service level is defined as the long term proportion of satisfied demand -- A greedy simulation–based heuristic is presented to find a feasible solution to the problem in a reasonable computational time
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    Ítem
    Analysis of chaotic behaviour in supply chain variables
    (Journal of Economics, Finance and Administrative Science, 2011-12) Peña Zapata, Gloria Elena; Ramírez Echeverri, Sergio Augusto; Universidad EAFIT. Departamento de Ingeniería de Producción; ramire@eafit.edu.co; gepena@unal.edu.co; Gestión de Producción y Logística
    In this article we develop a supply chain model of four levels through the utilization of system dynamics with Ithink® and Mathlab® softwares to analyze data -- The supply chain is studied from the chaos theory perspective, which helps identifying the sensitive variables that can lead to a state of chaos -- A generic structure model that comprehends factory links, distribution, wholesale, retail and the client is constructed -- The difficulty of operations and logistics managers to decide how much to order and when to do it is simulated accordingly to what occurs in the links of the preceding and subsequent levels with two decision parameters: The first parameter denominated A indicates the participation (between 0 and 1) of the number of product units that are taken into account in the actual stock and the pending orders at the moment of performing an order – Thesecond parameter, denominated B, is the participation (between 0 and 1) of the number of units in the supply line (in transit) at the moment of performing orders of each of the links of the supply chain