Search results for "Inventory management"
showing 9 items of 9 documents
DESMILS : a decision support approach for multi-item lot sizing using interactive multiobjective optimization
2023
AbstractWe propose a decision support approach, called DESMILS, to solve multi-item lot sizing problems with a large number of items by using single-item multiobjective lot sizing models. This approach for making lot sizing decisions considers multiple conflicting objective functions and incorporates a decision maker’s preferences to find the most preferred Pareto optimal solutions. DESMILS applies clustering, and items in one cluster are treated utilizing preferences that the decision maker has provided for a representative item of the cluster. Thus, the decision maker provides preferences to solve the single-item lot sizing problem for few items only and not for every item. The lot sizes …
Flexible Data Driven Inventory Management with Interactive Multiobjective Lot Size Optimization
2021
We study data-driven decision support and formalise a path from data to decision making. We focus on lot sizing in inventory management with stochastic demand and propose an interactive multi-objective optimisation approach. We forecast demand with a Bayesian model, which is based on sales data. After identifying relevant objectives relying on the demand model, we formulate an optimisation problem to determine lot sizes for multiple future time periods. Our approach combines different interactive multi-objective optimisation methods for finding the best balance among the objectives. For that, a decision maker with substance knowledge directs the solution process with one’s preference inform…
Current economic downturn and supply chain: The significance of demand and inventory smoothing
2014
The aim of this article is to analyse and quantify the effects of demand and inventory smoothing into supply-chain performance, facing the extreme volatility and impetuous alteration of the market produced by the current economic recession. To do so, we model a traditional serial three-stage supply chain and we test five settings of order smoothing under two shocks in the market demand, and we measure effects in terms of internal process benefits and customer service level of all supply chain partners. Results show that the implementation of this inventory strategy should be based on reward schemes; in fact a higher level of smoothing can generally improve the performance of the upstream st…
Integration of lot sizing and safety strategy placement using interactive multiobjective optimization
2022
We address challenges of unpredicted demand and propose a multiobjective optimization model to integrate a lot sizing problem with safety strategy placement and optimize conflicting objectives simultaneously. The novel model is devoted to a single-item multi-period problem in periodic review policy. As a safety strategy, we use the traditional safety stock concept and a novel concept of safety order time, which uses a time period to determine the additional stock to handle demand uncertainty. The proposed model has four objective functions: purchasing and ordering cost, holding cost, cycle service level and inventory turnover. We bridge the gap between theory and a real industrial problem a…
Shelf life-based inventory management policy for RF monitored warehouse
2018
Post-harvest losses of perishable products strongly depend on inefficiencies of the entire supply chain. In particular, these inefficiencies can be reduced by optimizing the warehouse management, taking into account the remaining shelf life of the product, and matching it to the requirements of the subsequent part of the handling chain. The replacement of First In First Out picking rule with Last Shelf Life First Out policy has been proved to improve the overall performance of the supply chain. The practicability of such approach is related to the possibility of monitoring the deterioration rate of the products and of predicting the residual shelf-life, that is mainly influenced by harvesti…
Discrete frequency models for inventory management – an introduction
2001
Abstract The paper deals with the problem of devising a periodic replenishment policy when orders must be periodic, but only a given, discrete set of order frequencies can be used. The multi-item, instantaneous replenishment case with known demand is studied. In particular, staggering policies somehow arranging replenishments not to come at the same time instants are considered. The paper is composed of three parts: first, a taxonomy of several versions of the discrete frequency problem is proposed, according to different elements; in the second part, a general mixed integer programming model is proposed which is able to capture the peculiarities of the whole spectrum of this kind of proble…
The Impact Of Demand And Inventory Management Policies On Bullwhip Effect In Production Networks
2004
The bullwhip effect is a phenomenon consisting in variance amplification of orders as they move up a supply chain. The immediate bullwhip effect consequences are the increase of inventory costs, poor custoiner services and inefficient utilization of resources due to the difficulties of production planning activities in highly variable conditions. There are many factors that cause the bullwhip effect, but if is particularly due to demand forecasting and inventory management policies. In this paper the impact on bullwhip effect of different policies to manage demand and inventories has been evaluated through discrete event simulation, using the ARENA (R) simulation package.
Interactive Multiobjective Optimization in Lot Sizing with Safety Stock and Safety Lead Time
2021
In this paper, we integrate a lot sizing problem with the problem of determining optimal values of safety stock and safety lead time. We propose a probability of product availability formula to assess the quality of safety lead time and a multiobjective optimization model as an integrated lot sizing problem. In the proposed model, we optimize six objectives simultaneously: minimizing purchasing cost, ordering cost, holding cost and, at the same time, maximizing cycle service level, probability of product availability and inventory turnover. To present the applicability of the proposed model, we consider a real case study with data from a manufacturing company and apply the interactive NAUTI…
Production Inventory and Enterprise System Implementation: An Ex-ante No-Cost Based Evaluation
2010
The objective of this paper is to present an Enterprise System (ES) ex-ante no-cost based three step evaluation technique, which enables a pre-emptive analysis of the effects of an ES implementation using a system of referenced non financial performance metrics. The innovativeness is in the use of a simulation model fully integrated with the evaluation procedure. Researchers can extend the presented technique to further modelling approaches and test it on different market sectors. The analysis provides practitioners with a measurement system that enables an analysis of the effects of a given ES implementation and can be further employed in financial evaluations.