Brazilian Republic Presidency Mobile Telephony Consumption Cost Reduction with Outliers Detection

After the Federal Court of Audit's decision on Judgment 1601/2005, the Brazilian Government has sought to reduce expenditure on telephone expenses. In this understanding, the Presidency of the Republic acquired Telecom Expense Management software, which proposes to provide telephone management, focusing on the efficiency in the use of resources and reducing the risk of having particular phone calls paid by the government. However, the software has not yet resulted in the volume of savings expected and required after the issuance of Decree 8.540/2015, which sets goals for reducing the consumption of resources with telephone expenses. The present paper studies the behavior of organization mobile phones of Brazilian Republic Presidency, in order to detect outliers through clustering processes as K-means, FarthestFirst and others, composed by calls registers with characteristics (time, duration and day of the week) that are not related to the corporation use. The results accused that 33 thousand calls were suspect of being private, about 10%, against 0.5% of previous solution and a confirmation that 90% of the suspicious calls obtained by the K-means method could be refunded in a sample presented to some employees of the Presidency of the Republic.