This paper aims to propose improvements to plastic waste management performance via Partial Least Squares Structural Equation Modeling (PLS-SEM) using a survey’s structured questionnaire and hypothesis testing. The methodology has been applied to the metropolis of Salvador, Brazil’s third most populated city, although it can be used for other cities worldwide. All the indicators, constructs, and hypotheses concerning collection, sorting, and recycling came from a literature review. The dependence of the performance on efficiency, effectiveness, the municipality’s socioeconomic aspects, and the municipality’s infrastructure was evaluated, and both academic and practitioner public representatives were surveyed. Since almost double the minimum number of respondents answered the questionnaire and the PLS-SEM statistics showed that the modeling presents consistency, the discussion is relevant. The final results show that the respondents rated the volume of processing to be slightly more significant than the market maturity for the effectiveness of plastic waste management, which in turn contributes to performance. Once the positive influence of the municipality’s infrastructure on performance has also been verified, the Deposit-Return Systems (DRSs) should be considered for improvement, in addition to an increase in the availability of selective collection systems, contributing to the growth of both the recycling rate and business profitability, reflections of performance.

The proposal of this research is the development of a hybrid multi-criteria decision analysis (MCDA) model of sustainability performance. The model is applied to a Brazilian oil and gas company and is constructed from the MCDA associated with statistical analysis. The MCDA technique is a preference ranking organization method for enrichment evaluation (PROMETHEE), with analysis of 20 indicators of the dimensions of sustainability. In the statistical analysis, the Principal Component Analysis (PCA) and Multiple Linear Regression (MLR) are used. The results of PROMETHEE showed that the company’s best sustainability performance was in 2011 and 2010. The worst sustainability performance was in 2015 and 2016. The application of the PCA technique aims to eliminate the existing multicollinearity and capture the direction of variability of the indicators. The first PC with 53.2%, the second PC with 25.6%. An estimate based on the MLR equation was performed. The limitation of the paper is with data from the company’s sustainability reports as well as the choice and quantity of indicators. The analysis of the sustainability performance of the company through multi-criteria models is not new but their combination with mathematical models, comparing the sustainability reports per year, brings more complete results on the sustainability performance of the company.

In the latest years, supply chain academics and practitioners have been increasingly concerned with the supplier selection problem. In this paper, a computational system based on 'Fuzzy Extended Analytic Hierarchy Process (Fuzzy AHP)' was developed for supplier selection considering risks. Specifically, we aimed to assess the use of the Fuzzy AHP method in supplier selection and to analyze the support of the proposed system to supplier selection considering risks through a practical application in the Brazilian oil industry. For this, the main criteria, sub-criteria, and alternatives for supplier selection were identified and comparatively assessed by expert managers from the focal company. Through the Fuzzy AHP computational approach the priority weights of each item were calculated. After computing the final score for each supply alternative, supplier