Desarrollo de un modelo matemático para el cálculo de stock de repuestos de mantenimiento de distribución y alumbrado público en base a la Norma EN 62550 en la Empresa Eléctrica Riobamba S.A.

Abstract

In the elaboration of this research project a mathematical model was developed in order to calculating the stock of maintenance spare parts for the distribution and street lighting areas, based on the UNE - EN 62550 standard, implemented in the Riobamba Electric Company S.A. (EERSA). Data were obtained from a track record of lightning poles in Riobamba city, Chimborazo province, that were statistically censored by their identification code and its last maintenance day, because they are necessary for the forecasting demand. Only 3 distributions of the norm were chosen, being Weibull, Normal and Logarithmic normal those most closely coupled to the available variable of failure time (TTF). Using the Kolmogorov Smirnov test, it was demonstrated that Weibull is the distribution that suits the best, then with the formulas described in the distribution, the average time until failure (MTTF) was calculated, subsequently with the stipulating hours for one year operation, the useful life resulted was 2 years, 7 month and 6 days until the failure for sodium lamps (Na), with this value, 3 years stock forecast was elaborated. Also, the ABC methodology was applied to determine spare parts that have the highest movement of expenses in the general warehouse during 2019, providing an optimization vision for the control and stock management. To obtain reliable results suitable to the reality, it is necessary to improve the link between the data of the general warehouse area and the distribution and public lighting area, it’s also important to train the maintenance, assets and reliability staff.