Statistical monitoring of the process of packaging of sausage by means of the control charts

Abstract

Control charts are used in process monitoring, focusing on quality by providing visual information on possible causes of variation, making it easier for corrective actions to be applied. The objective of this study is to apply Shewhart (X-S), CUSUM and EWMA graphs to monitor the weight of the hot dog type sausage package in a food industry. The data were provided by the company and the graphs elaborated in the software Statistica® 7. The results of each graph are compared in order to identify the best method to monitor the weighing process. It was observed that both CUSUM and EWMA graphs have as main positive point detect small deviations, providing information on trend, however, comparing them, the EWMA chart presents more quickly the first sign of uncontrolled process, therefore it is indicated for the monitoring of the sausage weighing process. In addition to this, complements the study with the cause and effect diagram is complemented, which is elaborated for analyze special causes. By using the EWMA chart to monitor the process the company may have increased productivity and decrease reprocessing.