One challenge related to contact center management involves determining which process best serves customers, inbound or outbound. Such decisions impact the number of service agents available for operations, affecting costs. The size of the call centers market worldwide is estimated to reach $337 billion dollars by 2018. This industry employs 670,000 people in Mexico. A series of equations for calculating the difference in the number of service agents required by the two processes is determined using the direct demo method. Developed theorems and corollary may help simplify decision-making processes. The findings demonstrate that the number of agents required for both processes depends on the percentage of customers served at each location and on service agent occupation rates. The study recommends some best practices to the Mexican call center industry in order to improve its profits and quality within the inbound outbound services.