THE USE OF THE PARETO-LORENZ DIAGRAM FOR QUAlitative ANALYSIS OF STEEL RIMS

Abstract

One of the most commonly used methods of quality management in manufacturing and industrial enterprises is the Pareto-Lorenz analysis. This method is currently one of the most frequently used conventional tools for the improvement the product quality and processes. It is a very useful tool used in the analysis of a production or service processes that generate variables that can be categorized. The Pareto-Lorenz chart is a graphical representation of the frequency of the causes of the problem (graph in the form of a bar graph) and their cumulative values (Lorenz curve). The impact of Pareto analysis on product quality occurs mainly through the analysis of the frequency and significance of non-compliance, elimination of quality problems occurring in the enterprise most often and elimination of quality problems generating the highest costs. The purpose of the work was to analyse the quality of steel wheels manufactured by one of the companies in Poland. Steel wheels are standard equipment on cars. Their biggest advantage is durability, both mechanical and chemical. As a result of the analysis, three main causes of steel rims complaints were identified. These are edge bumps, damaged coating (splinters) and material defects. The identified causes represent a good starting point for works aimed to propose concrete preventive actions which, if implemented, should reduce the number of occurrences of certain types of defects without the need for expensive large-scale actions.