Cassius Tadeu Scarpin

Otimização no serviço de saúde no estado do Paraná: fluxo de pacientes e novas configurações hierárquicas

Neste trabalho e apresentada uma proposta para a otimizacao no servico de saude no estado do Parana com relacao ao fluxo de pacientes dentro do estado e a regionalizacao (divisao) do estado, obtendo novas configuracoes hierarquicas para o mesmo. Quanto a regionalizacao, a proposta consiste em dividir o estado em regioes menores, formadas por varias cidades, vinculadas a uma cidade sede, principal responsavel pelo atendimento no seu nivel de resolutividade. Com relacao ao fluxo de pacientes, e proposto um algoritmo que, ao mesmo tempo em que organiza as informacoes, otimiza o fluxo. Ja para a regionalizacao, fez-se uso do algoritmo branch and price, que utiliza o algoritmo de geracao de colunas em cada no de uma arvore branch and bound. A tecnica proposta apresentada para otimizar o fluxo de pacientes mostrou-se eficaz e util, pois alem de fazer o controle dos procedimentos medicos realizados em cada cidade, tambem define para qual cidade o paciente deve ser encaminhado, respeitando a divisao hierarquica do estado. Ja o algoritmo branch and price, utilizado para a otimizacao na regionalizacao do estado, e bastante interessante, pois tenta melhorar a referida divisao hierarquica do estado, levando em consideracao o numero de habitantes e o numero de procedimentos medicos de cada municipio do estado. Os resultados obtidos tem atendido as expectativas da SESA-PR.

UMA NOVA ABORDAGEM HEURÍSTICA PARA A RESOLUÇÃO DO PROBLEMA DO ROTEAMENTO DE VEÍCULOS CAPACITADOS

Este trabalho apresenta uma nova abordagem heuristica para a resolucao do Problema do Roteamento de Veiculos Capacitados (PRVC). O metodo emprega uma estrategia em dois estagios, que consiste primeiramente em agrupar os clientes de acordo com a demanda e, posteriormente, construir as rotas para os grupos formados. Para o primeiro estagio, desenvolveu-se uma heuristica de ajuste para o algoritmo classico de agrupamento proposto por Teitz e Bart (1968). No segundo estagio, as rotas iniciais sao geradas pela heuristica de insercao mais economica e refinadas pelas heuristicas de melhoria 2-opt e 3-opt. A abordagem proposta foi testada para instâncias classicas da literatura, e comparadas com o desempenho de procedimentos exatos e heuristicos existentes, produzindo resultados interessantes, tanto em termos de eficacia quanto de eficiencia.

A methodology for minimizing LPG transportation impact

Purpose Liquefied petroleum gas (LPG) transportation risks depend on aspects such as the total length of the trip and population density along the route. Choosing to deliver the product on non-busy days and reducing distances travelled may help to reduce these risks and lower the level of air pollution generated by the transportation trucks. The purpose of this paper is to reduce LPG delivery impact. Design/methodology/approach A three-stage methodology is proposed. First, rules are created in order to choose which clients have to be visited each day to avoid deliveries in downtown areas during business days. Second, an Iterated Local Search (ILS) metaheuristic is proposed for the capacitated p-median problem to group the chosen customers. Finally, another ILS is proposed to solve the Travelling Salesman Problem, for each truck to follow a better route while visiting its customers. Findings The methodology resulted in a 24.8 per cent reduction in distances travelled, representing an annual reduction of 32,716 kg in CO2 emissions. The average amount of product sold per kilometre travelled improved by 72 per cent. Originality/value The literature shows a clear need for companies to consider sustainability in their daily decisions. However, especially in developing countries, there is a fear that protecting the environment may cost money. This main contribution of this paper is that it presents a real solution, serving as a guide for companies to improve their transportation system, resulting in environmental and economic benefits.

A multi-objective genetic algorithm based approach for location of grain silos in Paraná State of Brazil

Abstract The production of soybean and corn has increased steadily in Brazil, with the Parana State being the second largest producer of these grains. The increased production has now necessitated the storing facility also to be increased. Accordingly, partitioning the storage facility is a proposal to aggregate the municipalities of Parana into regions for effective transportation of the grains. Motivated by the requirement, the present work aims to organize the storage regions by aggregating the municipalities as a multi-objective graph (territory) partitioning problem with the municipalities being the nodes and roads linking them as the edges of the graph. In order to find the effective number of new silos to be constructed and their region-wise locations, maximization of the homogeneity of storage deficit and minimization of the inter-region product transportation cost from production sources to storage points are considered as two objective functions for the problem. A multi-objective genetic algorithm based results, presented here, should have a strong impact on the grain storage system management in Parana. Moreover, the proposed methodology might act as a useful grain storage management decision aiding tool in other territories.

The two-echelon multi-depot inventory-routing problem

Abstract This paper studies the application of the Vendor-Managed Inventory paradigm, when a vendor manages their own inventory in addition to those of its customers. We extend this concept by applying it to a two-echelon (2E) supply chain, in which the middle layer is responsible for managing pickups of inputs from suppliers and deliveries of final product to its customers. Inspired by a real case, we introduce 2E Multi-Depot Inventory-Routing Problem (2E-MDIRP). Different inventory policies are considered for managing the inventory of input and final products. We propose a mathematical formulation capable of handling all decisions of the system, and design a branch-and-cut algorithm to solve it. Moreover, we propose and implement a rich matheuristic algorithm to solve the problem efficiently even for very large instances. A flexible metaheuristic phase handles vehicle routes, while input pickups, product deliveries and routing improvements are performed by solving a subproblem exactly. We perform extensive computational experiments in order to evaluate the performance of our method, both by comparing the two algorithms, the effectiveness of the different inventory policies, the cost structure of the solutions, and the performance of different parts of the proposed heuristic algorithm. The results show that a more strict inventory policy leads to higher costs but fewer vehicle routes, which makes the overall problem easier to be solved by the approximated algorithm.

Confrontation between techniques of time measurement

Purpose The purpose of this paper is to present a precise comparison between a pre-determined time rules and the evaluation performed with the help of a manual chronometer using data from a line assembly in an automotive industry besieged in the state of Parana, Brazil. Nowadays, it is possible to verify several tools of measurement of task times, some taking less time and causing less wear of the evaluator than others, but not being in accordance with the real conditions of the workers of a certain industry. Design/methodology/approach The developed paper has its methodology based on two methods of time analysis, one of them being an adaptation of the MODular Arrangement of Predeterminated Time Standard (MODAPTS) method – called MODAPTS 2. This method is used by the industry in analyzed in this work and the other through the use of simple manual timing, through the digital timer, of the stages developed in a workstation. Findings The study shows that for each operation analyzed, thus presenting a situation of minimum waste, it becomes possible to judge which reasons exist for the operator during manual timekeeping not to reach the optimum times generated by the system of pre-determined times and movements (PMTSs) questioned. Research limitations/implications This study is conducted on an automotive enterprise in a period of confidentiality, which means that only a single workstation is able to be studied. This means that the comparison obtained between the time measurements methods used, and the evaluation of the MODAPTS is carried out with the best possible movements and gestures, disregarding then that the wastes can still be postulated to the whole assembly line. Originality/value With the automation in industry, where assemble tasks are usually developed manually, it is believed possible to discard the option of measuring task times in its classic and manual form, using a timer, yet during this process, there will be variables that may not be considered by pre-determined measurements methodologies. The work developed by this paper presents different variables that are not examined by the methods of PMTS, not frequently seen in the literature, as well as the difference that occurs between the measurement of times with stopwatch and the use of PMTS, which, in its original form, disregards the wastes that the operator has in their movements.

Políticas de distribuição com lote econômico de entrega em problemas de roteirização com estoque gerenciado pelo fornecedor e sistema logístico em três níveis

In vendor-managed inventory systems, logistics decisions are centralized at the vendor, allowing inventory storage and transportation costs to be reduced simultaneously. The operation of such systems requires the solution of a complex combinatorial optimization problem, known as Inventory Routing Problem (IRP), which involves managing client inventory and determining the frequency and size of product deliveries as well as the route taken by the vehicle over a given planning horizon. We present three new dynamic formulations for an economic order quantity distribution policy for the multivehicle inventory routing problem (MIRP). A mixed-integer linear programming (MILP) model with additional practical constraints was used for the MIRP, considering a three-echelon logistic system. A new heuristic approach that breaks the MIRP down into the following two sub-problems was also proposed: the first sub-problem deals with the scheduling of deliveries and the formation of delivery clusters over the planning horizon; the second sub-problem builds the routes for the delivery clusters using classic route construction heuristics and a procedure for intra-route improvements. Adjustments between routes are performed with the aid of a new large neighborhood search (LNS) strategy. Small, medium, and large scenarios with different storage and transportation costs were generated using parameters based on data from the literature. Extensive computational tests were carried out to determine the effectiveness of the proposed distribution policy and the heuristic used.

Uma proposta de modelagem matemática para o Problema de Roteamento em Arcos Capacitado e Periódico adaptado

Os problemas de roteamento em arcos tem grande aplicabilidade a problemas reais e podem ser abordados de diversas formas dependendo de suas restricoes. Eles consistem em determinar rotas para veiculos de forma que atendam um conjunto de arcos em um grafo. O objetivo desse artigo e apresentar uma modelagem matematica para uma adaptacao do Problema de Roteamento em Arcos Capacitado e Periodico. Atraves de programacao linear binaria pretende-se determinar uma rota para multiplos veiculos respeitando suas capacidades, considerando um horizonte discreto de tempo e que atenda as demandas de cada arco.

Proposal for a strategic planning for the replacement of products in stores based on sales forecast

This paper presents a proposal for strategic planning for the replacement of products in stores of a supermarket network. A quantitative method for forecasting time series is used for this, the Artificial Radial Basis Neural Networks (RBFs), and also a qualitative method to interpret the forecasting results and establish limits for each product stock for each store in the network. The purpose with this strategic planning is to reduce the levels of out-of-stock products (lack of products on the shelves), as well as not to produce overstocking, in addition to increase the level of logistics service to customers. The results were highly satisfactory reducing the Distribution Center (DC) to shop out-of-stock levels, in average, from 12% to about 0.7% in hypermarkets and from 15% to about 1.7% in supermarkets, thereby generating numerous competitive advantages for the company. The use of RBFs for forecasting proved to be efficient when used in conjunction with the replacement strategy proposed in this work, making effective the operational processes.

NOVAS PROPOSTAS PARA O PROJETO DE REGIONALIZAÇÃO DA SAÚDE NO ESTADO DO PARANÁ (SUS-PR) UTILIZANDO O ALGORITMO BRANCH-AND-PRICE

Neste trabalho sao apresentadas tres novas propostas para o projeto de regionalizacao da saude no estado do Parana. O projeto consiste em dividir o estado em regioes menores, em tres niveis hierarquicos: macro-regioes, regionais e micro-regioes. Cada uma dessas divisoes possui uma cidade-sede, sendo esta a principal responsavel pelo atendimento medico de sua divisao hierarquica. A formacao otimizada de grupos de cidades e o principal objetivo deste trabalho. O problema de otimizacao esta relacionado a definicao de p-medianas, em uma rede de n nos, de modo a minimizar a soma das distâncias dos pontos de demanda as p medianas mais proximas. Na solucao deste problema fez-se uso do algoritmo branch-and-price. Alem disso, combina-se a relaxacao Lagrangeana/surrogate com a geracao de colunas para fornecer colunas mais produtivas para encontrar a melhor solucao possivel. Novas configuracoes hierarquicas e novas politicas para as cidades-sede sao sugeridas neste trabalho. Os resultados mostraram-se bastante satisfatorios.