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A variety of problems related to waste management systems can be found in the literature, as they have become tougher to solve over the years. With this in mind, a report of the most influential research concerns in this field could help develop innovative works for solving waste management applications. Literature reviews appear in most introductions and discussion sections of research reports, case reports, and expert opinion papers. It was immediately observed that Cluster Analysis, a multivariate data mining technique, has been used in various applications for sustainability issues. For this reason, this paper shows the results of a Systematic Literature Review on Cluster Analysis techniques applied to waste management. This paper's primary goal is to detect what is happening with the applications and techniques in clustering techniques for waste management and, in this way, define possible gaps in this research field. The 61 analyzed papers were categorized into nine application types within the field of waste management (logistics/business; landfill research; theoretical/consequential; waste collection problems; location/selection; monitoring/decision support systems; leachate/water contamination; waste incineration/energy production and, waste forecast/waste production behavior). Following an analysis of their content, gaps were found related to exploring the complex situations in each problem. Instead of using general rules and constraints for their methodologies to solve real-world problems, they resorted to theoretical orientation solutions. Furthermore, suggestions from specialists in the field and more fitting constraints related to the data evaluated could make the works seem less theoretical and more visually applicable.

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Purpose The purpose of this paper is to present a precise comparison between a pre-determined time rules and the evaluation performed with the help of a manual chronometer using data from a line assembly in an automotive industry besieged in the state of Paraná, Brazil. Nowadays, it is possible to verify several tools of measurement of task times, some taking less time and causing less wear of the evaluator than others, but not being in accordance with the real conditions of the workers of a certain industry. Design/methodology/approach The developed paper has its methodology based on two methods of time analysis, one of them being an adaptation of the MODular Arrangement of Predeterminated Time Standard (MODAPTS) method – called MODAPTS 2. This method is used by the industry in analyzed in this work and the other through the use of simple manual timing, through the digital timer, of the stages developed in a workstation. Findings The study shows that for each operation analyzed, thus presenting a situation of minimum waste, it becomes possible to judge which reasons exist for the operator during manual timekeeping not to reach the optimum times generated by the system of pre-determined times and movements (PMTSs) questioned. Research limitations/implications This study is conducted on an automotive enterprise in a period of confidentiality, which means that only a single workstation is able to be studied. This means that the comparison obtained between the time measurements methods used, and the evaluation of the MODAPTS is carried out with the best possible movements and gestures, disregarding then that the wastes can still be postulated to the whole assembly line. Originality/value With the automation in industry, where assemble tasks are usually developed manually, it is believed possible to discard the option of measuring task times in its classic and manual form, using a timer, yet during this process, there will be variables that may not be considered by pre-determined measurements methodologies. The work developed by this paper presents different variables that are not examined by the methods of PMTS, not frequently seen in the literature, as well as the difference that occurs between the measurement of times with stopwatch and the use of PMTS, which, in its original form, disregards the wastes that the operator has in their movements.

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