QUALITY IMPROVEMENT USING ONE FACTOR AT A TIME (OFAT) THROUGH DESIGN OF EXPERIMENTS (DoE): CASE STUDY IN AN EXPANDED POLYSTYRENE (EPC) INDUSTRY

Abstract

Design of Experiments (DoE) is a statistical tool used in Six Sigma, a multifunctional tool that can be used in different situations, with the purpose of comparing different possibilities of the same system, with the screening of variables. This tool aims to obtain a project (process, product or result) with the best optimization of resources, in order to maintain the robustness of the project. Although the use of Six Sigma emphasizes the use of DoE, engineers still find it a difficult technique to apply and interpret. For this reason, the objective of this work is to present a methodology that tries to facilitate the implementation of DoE, as an approach to fill the gap between the technique and the daily practice of researchers and engineers, using the One Factor at a Time tool (OFAT). This is a simple and straightforward approach to conducting an experiment and analyzing the effects of individual form factors on a process or product in any organizational environment. An exploratory bibliographical research was carried out on the topic OFAT in the main databases. Next, a case study was carried out in an industry producing expanded polystyrene (EPS), to exemplify the use of the OFAT tool. From the various experiments carried out, it was possible to evaluate the use of OFAT tools which, despite using a simple methodology, leads to satisfactory results in terms of process improvement and the final quality of the evaluated product.