Maria Sameiro Carvalho’s research while affiliated with University of Minho and other places

Industries only survive in the modern business world if they are prepared to improve processes whenever it is necessary. Therefore, companies need to adapt and/or modify processes to improve the level of service and reduce needless costs. In this article the logistics problem of planning a ship load operation of a Portuguese cement company is addressed. The objective is to determine the best way to transport the bagged cement from the warehouse to a ship reducing costs and optimizing forklifts operations. A mathematical programming model is proposed showing this methodology as a powerful tool to provide effective support to a more intelligent decision process.

This article presents a project developed in a company’s quality department aiming at scheduling the nonconforming devices analysis’ process. The company faced a problem of low compliance with pre-established time requests, resulting in large fines paid to its customers of the automotive sector. In order to overcome this problem, scheduling tools were developed and tested, with the goal of minimizing the number of tardy tasks in identical parallel machines. The simulation of different scheduling rules allowed confirmation that the current prioritization rule is not the most effective one. Preliminary simulations were carried out using Lekin software [18], showing that other criteria promote better results. The use of a newly developed algorithm, combining two different criteria, resulted in a reduction of tardy tasks, thus decreasing tardiness fines paid to customers. Despite the preliminary status of present results, it is possible to foresee some improvements in the analysis process performance, by using decision making support tools based on scheduling algorithms. This way, a significant improvement on the number of analysis which fulfills the defined pre-requirements will be achieved.

A simulation model generator was developed to help a company of the Bosch Group to reduce costs in time and space with its warehouse. The simulation models are automatically created in Simio and can simulate pickers riding milk runs to collect containers from the warehouse, to satisfy the needs of production lines, assisting warehouse management by testing different storage strategies. Thus, the purpose of this paper is to present the developed generator and to use it in a case study, to test different storage policies for the company. The generator was validated, as was the simulation model automatically created. With this tool, some suggestions could be made to the company in question. Namely, it was shown that it would not be possible to maintain the FIFO rule and, at the same time, eliminate the upper floor of all racks for ergonomic reasons. To allow this, the rate of replacing containers should be synchronised with the needs of production lines. Alternatively, it was also shown that the performance of the warehouse would improve by dividing it into zones allocated to each milk run.

Home Health Care (HHC) is a growing industry in the medical services business, mainly in Europe and North America. These care services are provided at patients’ home by a multidisciplinary team using a distribution network. In this paper, an overview of the HHC services in Portugal and Brazil is presented. Additionally, a review is also presented to identify the main logistics problems associated with HHC services such as districting, routing and inventory management and the lack of integrated approaches to address them, as well as the best practices of management in the area. A framework is proposed to represent the main elements and characteristics of HHC services and their relationships. The framework suggests the use of a Decision Support System (DSS) based on optimization models and simulation approaches to overcome some of the main challenges associated to integrated approaches to address main problems, filling the gaps in the current literature. With the development of this DSS it will be possible to assist in the logistic planning of HHC teams, especially in countries like Brazil and Portugal.

Demand responsive transport (DRT) may be a feasible alternative when conventional transportation services provided by private companies are not available at a satisfactory level in terms of both price and quality. Nevertheless, these unconventional transportation systems are still not consolidated due to technical and economic issues. Beyond technical feasibility, DRT needs to be based on prices and pricing policies that ensure the attractiveness of the service without compromising its economic viability. Nevertheless, there is little evidence on the conditions of economic viability of DRT services and on the cost structure of such systems. In this article, we use a strategic activity based costing model to analyze the conditions of economic viability of a DRT system in a Portuguese rural municipality. The case presented was analyzed in terms of costs and profitability. They were defined a set of important variables which should be taken into account in the design and economic evaluation of DRT projects namely, ticket price, trip distance and passengers. Thus, this costing model can be used to assist decision making and support strategic and operational decisions. Furthermore, it can be embedded in a decision support system designed to support the real time operation of intelligent flexible transportation systems.

In this paper we discuss the use of discrete simulation technique to support the redesign process of an automated warehouse system of the Brazilian Air Force unit. This unit is responsible for the supply of all uniform items and other military support material to their military forces. In particular, our work aims at analysing the inclusion of an automated sorting system to prepare uniforms individual kits in order to release downstream supply chain from this task. The main challenge was to investigate the impact on the existing storage system of a new sorting system and, simultaneously, to explore if additional management measures are required to satisfy both throughput levels and overall supply chain requirements. To accomplish a solution for such a complex problem simulation models were developed using ARENA software. Results have shown that the use of simulation allows not only the assessment of the impact of the new sorting equipment but also to test different warehouse management strategies that should be adopted concurrently to ensure that desired throughput levels can be achieved in the new scenario. In fact, this research illustrates the flexibility of the simulation tool to address several complex management issues simultaneously such as the introduction of picking sequencing rules, the use of a class-based storage policy, the addition of new picking stations, and an increase of the number of the available boxes used for transportation.