PRODUCTION PLANNING MULTI-PRODUCT AND MULTI-MACHINE PROBLEMS IN ORDER TO MAXIMIZE THE ECONOMIC PERFOMANCE

Este artigo propõe um novo método que visa à maximização do resultado econômico operacional, através do planejamento de produção. O modelo utiliza um algoritmo de otimização que envolve quatro áreas de análise: mercado, produção, custos e por fim o resultado econômico. O objetivo é a maximização do lucro. A aplicação do modelo ocorre em uma empresa de manufatura que tem se caracterizado por alta variabilidade na definição dos preços de venda. Os resultados deste estudo indicam que pequenas variações nos preços de venda podem comprometer substancialmente os lucros globais do sistema produtivo

Coordinating ordering and pricing decisions in a two-stage distribution system with price-sensitive demand through short-term discounting

We consider a short-term discounting model in which the distributor offers a discounted price for the retailers' orders placed at the beginning of its replenishment cycle, in a non-cooperative distribution system with one distributor and multiple retailers, each facing price-sensitive demand. We examine the value of the price discount strategy as a mechanism for the distributor to coordinate the retailers' ordering and pricing decisions under two common types of demand, linear demand in price and constant elasticity demand in price. Our numerical study reveals that, in the presence of homogeneous retailers (namely, retailers with identical demand rates), the distributor's profit improvement due to coordination generally decreases as the number of retailers or the inventory holding cost rate increases, but increases as price elasticity increases. Although an increase in the inventory holding cost rate has a negative effect on the distributor's profit, it may have a positive effect on the retailers' profits. We further find that with heterogeneous retailers (namely, retailers with different demand rates), offering a discounted price under linear demand benefits the distributor when both the inventory holding cost rate and the variation in demand are either small or large. This cross effect, however, is absent under constant elasticity demand.Coordination Price discount Supply chain Short-term discounting

Development of an integrated discounting strategy based on vendors’ expectations using FAHP and fuzzy goal programming

The main goal of a company is to increase its market share and total profits at the same time. However, these two objectives conflict if discount rates are applied to vendors. The objective of this paper is to develop an integrated discounting strategy method to effectively manage the trans­actions of the vendors by determining the optimum discount rates which balance the increase on the market share and the total profit. With the proposed methodology which utilizes fuzzy analytic hierarchy process and fuzzy goal programming, determination of the discount rates of each vendor under different discounting strategies is facilitated. This enables the vendors to choose the most suitable discounting strategy with the best applicable discount rate and enables the managers to predict the transactions of the vendors. The proposed method is validated with a numerical study conducted on a pilot region of an international company. First published online: 07 Mar 201

Decentralized and centralized supply chains with trade credit option

The notion of a trade credit period is a common business practice, where a supplier allows a buyer a specified period to make a payment in full for a purchase made. The objective of this thesis is to explore the role of such a credit payment option in supply chain management. Towards this end, a two-echelon supply chain, consisting of a single supplier (e.g. manufacturer) and the cases of both a single and multiple buyers (e.g. retailers) is examined under decentralized (independent) and centralized (coordinated) decision making scenarios. The major emphasis of this research is limited to the case of a single product with price-sensitive deterministic, as well as stochastic market demand.The conditions under which a trade credit period should be offered and its appropriate length are determined from the supplier’s perspective under the decentralized case. Under the centralized decision scenario, the efficacy of a trade credit policy as a supply chain coordination mechanism is thoroughly analyzed and guidelines for pricing, production and delivery decisions are developed. The concepts developed in this study are illustrated via a number of numerical examples, in conjunction with thorough sensitivity analyses involving some selected problem parameters.The major contribution of this thesis is that we incorporate the pricing and inventory issues in supply chains with an endogenous credit payment period. This is the first study that examines the efficacy of trade credit option as a coordination mechanism. We propose a coordination mechanism that coordinates the supply chain, when a trade credit by itself is not sufficient to serve such a purpose, while preserving the benefits of a trade credit option. Also, this study is the first to examine the issues concerning trade credit under price sensitive stochastic demand. Another first for this work is the exploration of the implications of a trade credit policy in supply chains consisting of multiple competing retailers. The effects of the extent of competition and the market size on trade credit policy are evaluated. Our analyses lead to some important practical implications, to serve as managerial guidelines.Ph.D., Decision Sciences -- Drexel University, 201

Diseño de una metodología de gestión de inventarios para la integración y colaboración en la cadena de suministro del sector madera y muebles de Barranquilla

Ingeniería IndustrialThe Integration and collaboration in supply chains have been a topic very discussed in the last decades and have brought many benefits such as the reduction of the bullwhip effect, costs saving in logistics operation, among others. The Wood and Furniture Industry of Barranquilla presents weaknesses in inventory management because they have not adopted the best practices to manage the inventories of way collaborative and integrated between the different members in the supply chain. The aim of this research is to design a methodology of inventory management that seeks to improve the current levels of integration and collaboration in the supply chain of the wood and furniture sector in Barranquilla, establishing recruitment policies and integration and collaboration schemes. To achieve this aim, we designed a poll to characterize the sector being obtained levels of internal integration (medium), external integration (low) and collaboration (low). Similarly, the characterization of the sector and a review of the state of the art allowed doing a gap analysis against the best practices to global level and then proposing a methodology for inventory management that allows close those gaps.La integración y colaboración en cadenas de suministro ha sido un tópico muy abordado en las últimas décadas y ha traído consigo muchos beneficios como la reducción del efecto látigo, ahorro de costos en la operación logística, entre otros. El sector madera y muebles de la ciudad de Barranquilla presenta deficiencias en el manejo del inventario debido a que no se han adoptado buenas prácticas para gestionar los inventarios de manera integrada y colaborativa entre los distintos actores de la cadena de suministro. El objetivo de este trabajo de investigación es diseñar una metodología de gestión de inventarios que busque mejorar los niveles actuales integración y colaboración en la cadena de suministro del sector madera y muebles de la ciudad de Barranquilla, en el que se establezcan políticas de contratación y esquemas de integración y colaboración. Para lograr este objetivo se diseñó una encuesta que permitió caracterizar al sector obteniéndose niveles de integración interna (medio), integración externa (bajo) y de colaboración (bajo). De igual manera, la caracterización del sector y una revisión del estado del arte permitieron hacer un análisis de brechas frente a las mejores prácticas a nivel mundial para luego proponer la metodología de gestión de inventarios que permita cerrar esas brechas

Supply chain management for the process industry

This thesis investigates some important problems in the supply chain management (SCM) for the process industry to fill the gap in the literature work, covering production planning and scheduling, production, distribution planning under uncertainty, multiobjective supply chain optimisation and water resources management in the water supply chain planning. To solve these problems, models and solution approaches are developed using mathematical programming, especially mixed-integer linear programming (MILP), techniques. First, the medium-term planning of continuous multiproduct plants with sequence-dependent changeovers is addressed. An MILP model is developed using Travelling Salesman Problem (TSP) classic formulation. A rolling horizon approach is also proposed for large instances. Compared with several literature models, the proposed models and approaches show significant computational advantage. Then, the short-term scheduling of batch multiproduct plants is considered. TSP-based formulation is adapted to model the sequence-dependent changeovers between product groups. An edible-oil deodoriser case study is investigated. Later, the proposed TSP-based formulation is incorporated into the supply chain planning with sequence-dependent changeovers and demand elasticity of price. Model predictive control (MPC) is applied to the production, distribution and inventory planning of supply chains under demand uncertainty. A multiobjective optimisation problem for the production, distribution and capacity planning of a global supply chain of agrochemicals is also addressed, considering cost, responsiveness and customer service level as objectives simultaneously. Both ε- constraint method and lexicographic minimax method are used to find the Pareto-optimal solutions Finally, the integrated water resources management in the water supply chain management is addressed, considering desalinated water, wastewater and reclaimed water, simultaneously. The optimal production, distribution and storage systems are determined by the proposed MILP model. Real cases of two Greek islands are studied