Modelo multicritério utilizando-se Lógica Fuzzy como ferramenta de análise de viabilidade e tomada de decisão em obras rodoviárias

Abstract

With the globalization of the economy in recent decades, investment in transportation infrastructure has been the subject of study due to its important role and high added value. In Brazil, the road transport mode stands out among others and its direct influence on the entire cost of the production chain is constantly analyzed in order to achieve higher quality and lower cost. Thus, this study aimed to propose a multicriteria model to assist in decision-making regarding construction processes of infrastructure works, specifically in the road sector. For this, Fuzzy Logic was used, building a simulation model, where the input variables are the quantity of factors that add cost to the road, the complexity caused by the length of the section to be built, and the levels of environmental thermal stress to which the workers are subjected during the execution of the work. The output variable is the economic viability of the project provided by the combination of linguistic terms of input. Through literature review and expert experience, consistent methodologies were employed to support decisions in the model testing stage, in order to have a real system that optimizes available resources and maximizes project value. For the construction of the activated rule base, 45 rules were generated using the propositions AND, IF, and THEN, interacted by the Mandani method. After the construction of the model, information from twenty road projects of the DNIT was used in the test, with the return being verified consistent with the documented real information. The results showed the following: 1) HDI plays a significant role in the viability of the work in different environmental contexts: sections with critical lengths are susceptible to safety problems and increased operational costs, and sections with intermediate length in transition should be analyzed in conjunction with other variables; 2) HDI, alone, does not exert a significant influence on Viability when up to 5.5 criteria are met; however, if around 8 criteria are met in the project, the HDI becomes a high-impact factor on viability, because if it is in the comfort region, the viability is considered ideal, and if it is in the stress regions due to heat or cold, it returns a normal viability of the road project; 3) there are direct relationships between Section-Length and Criteria-Met when they are in the "Poor" range, which means that the Economic Viability of the project is well below ideal, at approximately 9%; 4) when the Section Length is classified as "Ideal" and the Criteria Met are at the "Good" level, Economic Viability reaches the highest level of 92.4%, indicating a very profitable project condition; and 5) Considering fuzzy simulations that encompassed the three input variables in different scenarios, with optimal and extreme values, the results obtained demonstrated coherence with the output variable, Economic Viability. After calibrating the model, a simulator with a high degree of precision was obtained by redoing real situations including their limitations, which can be used as a support tool in management and decision-making, aiming to minimize costs and seek constructive quality of highways.