Statistical analysis of stoppages in a metal stamping line: Case study

Abstract

Purpose: This article seeks to establish a statistical analysis to estimate the time of stoppages in a stamping line, which have a high variability that generates an unreliable scenario for the production program. Likewise, this document shows the methodological sequence to carry out a statistical analysis in a case study at an industrial level, considering variables of a real scenario.Design/methodology/approach: The methodological sequence is divided into five stages. Initially, the information of the stamping process was collected, later the types of stoppage were categorized according to the characteristics of the process. A collection of historical data information on stoppage times was carried out. With the information collected, the percentage frequency of occurrence of stops due to tool changes and incidents in the process was determined, and they were characterized by a Weibull distribution. Finally, to verify the effectiveness of the downtime behavior, a model was developed to simulate the availability of the stamping line in the Vensim Ple ® program.Findings: The model showed that the frequency analysis and the Weibull distribution obtained a similar behavior to reality. The study verified that it is necessary to establish a categorization of the characteristics of the downtimes, according to the characteristics of the pieces produced to evaluate the information, in this way, the times of change by tooling were established through a frequency of use and the stoppages by additional incidences to the process were better.Research limitations/implications: The basis for this study is the reliability of the information, especially in the data record. It has the disadvantage that the bias of the analyst is present when the information is recorded and analyzed.Practical implications: The methodology presented in this article is a reference for industrial applications in which it is required to establish improvement scenarios based on the reduction of stoppages present in the production lines.Originality/value: The importance of this study is that it was possible to establish a suitable workload allocation in the presses to optimize production.