Previsão de risco de atraso na execução de obras públicas por meio da lógica fuzzy: estudo de caso na cidade de Manaus

Abstract

The occurrence of delays in public constructions is not uncommon, as their execution deadlines are often extrapolated, even though such deadlines are obtained through preliminary technical studies. The causes that originate such delays are varied, ranging from rainfall to increases in quantities of existing services or increases in new services. In this research, we sought to obtain a procedure, using fuzzy logic, to predict the risk of delay that some variables may cause in the period of execution of the work, allowing a public administration or a contracted company to adopt measures that they consider essential for mitigation of this delay. Initially, documentary and bibliographic research was carried out in order to identify the causes that most contribute to the occurrence of delays in the works. Once these causes were identified, the construction of the fuzzy inference system was started, with six of the most significant causes identified in the research being considered as linguistic variables, namely: the hiring factor, which corresponds to the quotient between the value of the proposal of the company and the amount budgeted by the administration; the value of the work, which is the value of the contract for the work; the executive design, which are the engineering designs used; the change in quantities, which are changes in the quantities of existing services or addition of new services; authorization from public agencies, which corresponds to the permission or support of any public agency or public company for the execution of the work; and the rain. For simulation of the created fuzzy inference system, real data from four public works were entered, and the answers of this simulation were satisfactory, due to the fact that they are confirmed by the documentation of the respective works. It is concluded that the system proved to be useful, as it was possible to predict the risk of delay in the execution of public works in the city of Manaus, and it can be used by both the public administration and the contractor to mitigate the causes of delays in the execution of public works.