Control estadístico de calidad de los procesos de producción en carrocerías Yaulema Jr. con respecto al forrado y acabados de la estructura de la ciudad de Riobamba

Abstract

The objective of this study was to perform a statistical quality control of the production processes in Yaulema Jr. bodywork with respect to the lining and finish of the structure to improve the quality of the final product. The population was formed by the units on request for eight months, in the bodywork company Yaulema Jr. In the Calpi parish, Riobamba canton, Chimborazo province in the period 2021. The study considers the production processes in the manufacture of buses, formed of the defects caused that were extracted by means of quality control tools such as observation and verification sheets in a sample of seventeen bodies, later a descriptive statistical analysis was done which shows the behavior of each process, the Shapiro-Wilk normality test was applied to the three production processes, a random vector was considered to test trivariate normality, a relationship between variables was shown by joint correlation and the Bartlett sphericity test was applied, multivariate normality and joint correlation were verified and it was possible to apply multivariate control charts with the Hotelling’s T2 test and univariate letters of type c and u. It is concluded that the production processes follow a trivariate normal distribution and are jointly correlated, applying the multivariate control charts the result was that the unit two is outside the upper limit and the process is out of statistical quality control due to special variations causes while individually the three processes are under statistical quality control. It is recommended in order to obtain better results that a detailed control of each unit should be done to avoid loss of information, so that the quality of the bodywork can be more accurately evaluated.