1,721,117 research outputs found

    Value Stream Maps and Critical Path Method for production and procurement planning: a Make To Order company

    No full text
    The concept of Value Stream Map (VSM) is inserted as key point in Lean Manufacturing (LM). VSMs, originally named "material and information flow maps", allow a one page diagram representation of the whole process required to realize one or more final products. Because of this they are a common tool used to describe production processes and to underline the business areas in which wastes are identified. Nevertheless the aim of this paper is not to introduce a practical example of VSMs implementation, how to define a new approach that uses VSMs as tool to support production and procurement planning according to scarce resources capacity over a critical production path. This approach is articulated on 5 sequential steps and integrates the classical technique of VSMs with tools characteristic of planning theory like Critical Path Method (CPM) and capacity planning techniques like Rough Cut Capacity Planning (RCCP)

    Optimal Control of Distribution Chains for Perishable Goods

    No full text
    A discrete-time dynamic model of distribution chains for perishable goods is presented together with an approach for its optimal management based on model predictive control. The model is based on a directed graph, with buffers representing the amounts of goods for the various remaining lifetimes, whose time evolution is obtained via balance equations. The amounts of goods to transfer from node to node are chosen by solving a receding-horizon optimal control problem at each time step. The proposed approach allows one to trade among inventory and transportation costs, satisfaction of the customers' demand, and reduction of the amount of wasted goods, namely goods with no remaining lifetime and thus that have to be discarded from the distribution chain. Preliminary simulation results in three scenarios are reported to show the potential of the proposed approach

    Reflective Simulation For On-line Workload Planning and Control

    No full text
    Since its beginning, simulation has been used to study complex systems in order to infer on their future behavior, in this field several applications have been made using it as off-line tool for strategic level choices. In modern application, especially in the field of industrial automation, on-line simulation has been extensively used for supporting operative decision trough a classical schedulesimulate loop. The paper presents an application of on-line simulation to the distribution logistics sector: a department store is here controlled by on-line simulators able to help decision maker to decide how many counters to kept opened or how many people to use for shelves replenishment. Since this exercise could seriously affect the performances of a real life department store, the methodology is, in fact, very sensible to parameter settings, a nested simulator has been implemented and used for algorithm fine tuning and critical parameter choice
    corecore