ABSTRACT The choice and distribution of the optimal fleet mix of helicopters to service the offshore air operation is an important logistical problem that has a potential to reduce costs considered in the oil and gas industry. The variability of helicopter models and sizes, as well as the possible operational restrictions of airport bases and airspace, requires that adequate numerical techniques of Operational Research are applied. In this context, this work develops a model to determine the trajectories and distances traveled between airport bases and offshore maritime units and vice-versa, through an airspace modeled by a directed graph. Also develop a helicopter performance model to obtain the estimated payload and flight times for each specified mission and last but not least an integer linear programming model to allocate an optimal fleet and airport mix for passenger transport through the use of different helicopter sizes. The model was applied to offshore units operating in the Santos basin due to their strategic importance in the oil and gas industry. The results obtained included a map of preferred regions for two different helicopter sizes (large and medium), the weekly flight tables showing the allocation of helicopters and airport for different demand scenarios, additionally the impact of fuel prices on different airport bases and the concentration of movements on air routes are also evaluated in order to complement the analysis.

ABSTRACT This paper aims to support decision-making for the return of classes to determine actions to reduce the problems arising from the pandemic through a multi-methodological approach using Value-focused thinking (VFT) and Rich Picture (RP). The case study includes a Brazilian small university, in a region with social and economic vulnerability. Six stakeholders representing the students, the municipality community and the university were interviewed from which the hierarchy of fundamental objectives and an objectives’ network unfolded in education, health, and community were created. Even though health concerns were shared by all stakeholders, these networks revealed a variety of perspectives not typically discussed in large universities, such as access to information and communication technologies; awareness of biosafety measures; and real estate vacancy. These findings indicate that future research should address the specific needs of small universities in vulnerable cities, particularly those in developing and underdeveloped countries, where universities’ presence fosters the economy.

ABSTRACT The COS method was introduced in Fang & Oosterlee (2008) and then was applied to pricing a variety of stock options for continuous random variables. This paper adapts the Fourier-cosine series (COS) method to recover discrete probability mass functions. We approximate mixture and compound probability distributions with cosine series. Enormous precision and computational speed are the qualities of the function estimates here obtained. We also develop the pricing framework to trade derivatives subject to discrete random variables. We apply the method to calculate, for the first time, the price of an interest rate derivative of recent vintage introduced in the Brazilian financial market. Parameter calibration confirms the quality of the model.

ABSTRACT This work considers the strategic Supply Chain Network Design (SCND) problem, which is to define the number and location of facilities, and the flow of products among them to fulfilling a long-term deterministic demand. A two-phase heuristic approach was specially developed to solve large scale problems in reasonable time, extending a previous algorithm introduced in Farias et al. (2017). In the construction phase, a multi-start approach was developed to generate diversified initial solutions from each new iteration of a layered-based rounding heuristic. In the second phase, a local search heuristic improves the solution provided by the rounding method. The solution method is evaluated using randomly generated instances, and a evaluated strategic of marketing in a real case study applied to a company to redesigning the supply chain to two lines of products.The obtained results evidence the effectiveness and flexibility of the developed approach for handling very large instances.

ABSTRACT This paper presents an actual application of the FITradeoff method to support strategic decisions on military budgets. Using Optimization Techniques and a particular Multicriteria Decision Aid method to assess budget allocation efficiency, a model was built for the Brazilian Defense Ministry. A case study of the Brazilian Navy is described in this paper, whereby this model was used. The focus is on the adaptations of FITradeoff necessary to make it suitable for different groups of decision-makers and staff, performing different tasks on the process. The FITradeoff proposal allowed a group decision with different levels suitable to the military context and high-level strategic decisions. The use of multicriteria in this approach provides a meaningful utility measure. This provides a score value representing the desirability of an alternative, in terms of its attainment of the institution’s strategic objectives. The approach contributed to an approximate gain of 15% in budget efficiency in 2022.

ABSTRACT Mobility and urban planning are challenging tasks for public authorities, especially in densely populated cities. The city of Olinda, Pernambuco-Brazil, faces problems in traffic and access to places, making it necessary to identify new alternatives to improve urban mobility in Olinda. This study presents a decision support model to develop and evaluate new alternatives to do so. In the decision frontend, Value-Focused Thinking was applied to identify objectives and their respective attributes, and to create alternatives based on these objectives. As a result, 69 alternatives were generated, concatenated into 48, and categorized into four groups. Group 1 and Group 2 comprise 30 alternatives that serve the city’s north side; however, they attend to the neighborhoods separately. Group 3 comprises 11 alternatives routes that serve the two areas together, this being the focus of this study, and Group four consists of 7 short-term alternatives. In the decision backend, the FITradeoff for ranking problematic method was applied to evaluate the 11 alternatives of Group 3. The study showed that it would be possible to improve mobility more urgently by making a few improvements to the itinerary on the existing routes. Therefore, the study discusses the possibility of starting to make progress in the urban system of the city by using fewer complex alternatives compared to setting up new routes.

ABSTRACT Since most of the studies about outsourcing are focused on mathematical models, this paper seeks to support from theoretical bases the use of partial information to ease the decision-making process; the practical contribution is to apply the FITradeoff method for solving a multicriteria problem of an agricultural research company that seeks to decide about the need to outsource the operation in case to overhead the limited capacity of the analysis services. After the FITradeoff method was applied to elicit preferences from each decision-maker (DM), the results show whether or not it would be feasible to outsource a given service, and what the most promising options are. The method required the DMs to answer in less time only a few questions, which avoided placing an unnecessary cognitive burden on them and proved to be useful in assisting DMs in the decision-making.

ABSTRACT This paper presents a broad overview of main contributions related to the FITradeoff (Flexible and Interactive Tradeoff) method. FITradeoff is a multicriteria method developed within the scope of the Multiattribute Value Theory (MAVT), considering partial information from the decision maker (DM) in the preference modelling process. Over the last few years, several methodological developments on this method have been published in the literature, as well as practical applications to a wide range of multicriteria decision problems. The most recent methodological advances are related to preference modelling process, which now integrate the two paradigms of elicitation by decomposition and holistic evaluation. Furthermore, contributions from behavioral studies, some of them including decision neuroscience, have enhanced the DSS free available for FITradeoff. In this paper, all previously developed works related to the FITradeoff method are approached, considering both methodological developments and practical applications. A summary on the different modeling approaches for solving different decision problematics (choice, ranking, sorting and portfolio) with FITradeoff is presented. The recently proposed combination of preference modeling paradigms - elicitation by decomposition and holistic evaluation - within the FITradeoff decision process is explained, as well its potential advantages for the elicitation process. Moreover, a brief review on the practical applications of the method in different contexts is presented. In addition, this work also brings a summary on the results of behavioral experiments conducted using neuroscience tools with the FITradeoff method, as well the methodological insights resulted from them, and future perspectives of potential research topics related to the FITradeoff method.

ABSTRACT The COVID-19 pandemic has affected everyday life in societies around the world. One of the most severe consequences has been the social isolation imposed by this extremely contagious disease. In this context, many people began looking for a pet for the first time. In Brazil, for instance, the pet sector increased its financial returns in 2020. In addition, companies that produce pet foods have experienced problems with the supply of materials. Supply chain disruption is a problem faced by many different organizations during this time of crisis. This study, therefore, investigated the supply of raw materials stored in the silos and tanks of a large company. This company have operations in 80 countries across the world and produces different products, including pet food. Thirteen raw materials used to produce pet food were considered. In addition, eight criteria of the company’s supply process were identified and explored. Moreover, the Flexible and Interactive Tradeoff (FITradeoff) method, which is a Multiple Criteria Decision Making/Aiding (MCDM/A) method, was applied to rank the raw materials based on supply difficulty. In terms of supply criticality, the order of materials was established from less critical to most critical. These results can be used by companies to better plan the receipt of these materials to reduce the risk of supply chain-related disruptions and propose better ways to distribute activities between planners to help them in their daily management.

ABSTRACT The goal of this study is to propose a decision model for supporting the choice of the best-agile model, based on the Flexible and Interactive Tradeoff (FITradeoff) method. This study provides the definition of an extensive set of 38 measurable criteria that were considered for evaluation of the most popular agile process models used in small and medium-scale enterprises. To illustrate the application of the model, we applied it to a set of alternatives that includes DSDM, SCRUM, XP2 and Crystal and an experienced project manager acted as our decision maker during the interactive elicitation process of the FITradeoff. The results show that the FITradeoff is very valuable for this class of problem because of its strong mathematical foundation and the possibility of combining two different ways for modeling the preferences of decision makers, which makes the process cognitively easier than other multi-criteria methods and increase the confidence on the results. Although our study focuses on the context of small and medium-scale companies for software development, the approach can be used to other types of environments, including distributed software development and large enterprises.

ABSTRACT This study targets six North Asia and African hospitals that provide clinical treatment, diagnostic, and consultation services. The study revealed a lack in the selected hospitals’ infrastructure to support implementation successfully Environmental Management Systems (EMS). A factor analysis was performed based on five factors; EMS efficiency, the hospital’s culture, support from top management, legislation, and time and budget controls. Out of 23 sub-factors tested, it has been found that 7 of them can control the differentiation of the factors. The results highlight human errors in chemical and medical materials that lead to environmental pollution. It was followed by a sub-factor that indicated that controls of hospital activities and correction of its performance depend on the feedback received from the environmental information system. The study’s main conclusion is that recovering green hospital systems depends on successfully carrying out the ISO 14001: 2015 standard.

ABSTRACT This study analyzes performance measures in a Call Center with impatient customers, who may leave the system before being served. The abandonment of the waiting line is a measure of the subjective perception of the quality of the services offered, being one of the main concerns of the managers of Call Center systems. Based on data extracted from the case study of a Brazilian company, it is shown that the analytical queuing models M/G c /1+G and M/G/c+G, with generic distributions to represent service times and generic distributions (particularly mixed distributions) to represent patience times, can be effective to evaluate the congestion problem of this Call Center. The sampling performance measures of this case are compared with the measurements obtained through the M/G c /1+G and M/G/c+G models, using non-mixed and mixed distributions based on Exponential, Fatigue Life and Normal distributions to represent customers’ patience. We are not aware of other studies in the literature in this line of research. The results indicate that, in general, the use of analytical queuing models with abandonment, exploring more elaborate distributions to model service times and mixed distributions for patience times, are more accurate in evaluating this Call Center than other queuing models with abandonment, such as the M/M/c+M, M/M/c+G and M/G/c+M.

ABSTRACT In this research article, the service provision in a public company was evaluated through multivariate statistical control to determine the performance of its dimensions. For this purpose, the methodology used was: 1) characterization of the information associated with the quality dimensions provided, through consolidated databases recognized for their high level of quality, such as: Elsevier, Inderscience, among others; 2) calculation of Six Sigma metrics (DPMO, Z-level and performance), which will allow from a monthly average, to evaluate the quality of the service provided by the company in a timely and periodic manner in the 12 periods of 2019; 3) Evaluation of the performance of the service dimensions in a global and comprehensive manner, through multivariate analysis. Finally, the quality of the company’s service is presented. Thus, allowing the control and continuous improvement of the processes, through its prompt replanting.

ABSTRACT Air traffic management has become increasingly complex due to the increasing use of air transport. One of the main management bottlenecks is planning the efficient use of runways for takeoff and landing. This paper aims to investigate the Aircraft Landing Problem, which seeks to minimize earliness and tardiness in aircraft landing time, assigning them to a runway to land and sequencing them. A new mathematical formulation based on Job Shop was proposed for the problem, comparing it with four mathematical formulations in the literature; three directly comparable and another containing a particularity that does not allow a direct comparison with the other formulations. Computational tests were performed on 49 instances of the literature using the Gurobi Optimizer optimization package. These mathematical formulations commonly used for the ALP present difficulties in finding the optimal solution when the number of aircraft to land is large, i.e., more than 50 aircraft. Therefore, we proposed a matheuristic to solve instances with a greater number of aircraft than the Gurobi Optimizer cannot solve optimally. This matheuristic first finds an initial solution using relax-and-fix (RF) and then fix-and-optimize (FO) improves the found solution. Comparisons were also made using the first feasible solution obtained by Gurobi and then was improved with FO. Among the matheuristic variations, the one that obtained the best result was the combination of RF with FO and this also showed efficiency in relation to the work in the literature that uses FO.

ABSTRACT Private banking is one of the most profitable services offered by financial institutions in Brazil. In this service, a client should consider the suitability of a range of banking product, during his or her life based on dynamic objectives. It is a very complex service that involves regulation from governmental agencies, financial institutions’ interests, and clients’ objectives. It is not uncommon for these aspects to be conflicting, hindering the decision-making process and leading to unwanted decisions. This paper describes the development of a decision support system (DSS) for private banking, called OptPrivate, that integrates the suitability assessment with the portfolio selection, enabling the investor to choose a portfolio based on several and conflicting objectives. The DSS considers the investment selection problem in two interconnected subproblems: suitability and capital allocation. In the former, the DSS is based on an integrated modeling approach that considers legal aspects and investors’ preferences throughout a fuzzy multiple-attribute decision-making approach (MADM), called FTOPSIS-Class. In the latter, a fuzzy multi-objective optimization model uses the sorting results from the previous step to define a portfolio, simultaneously considering risk, return, and the investor’s profile. To facilitate the DSS application, linguistic variables are used in several aspects of the decision-making process, including risk exposure. The DSS was validated using field tests at a well-respected private bank in Brazil. The DSS recommends more suitable portfolios, in line with the investor’s profile, with greater profitability and less volatility than those recommended by the financial analysts for all test cases.