The objective of the thesis is to develop a discrete event simulation model able to address the problem of sizing the customer service desk of Skylogic. Skylogic is the Italian subsidiary of Eutelsat, one of the most important satellite telecommunications companies worldwide. After the relocation of the first level service desk, the company needed to investigate the performance of different scenarios, to understand if the possible scheduling and sizing respect the objectives set by the Service Level Agreements. The thesis describes the creation of a model that can enable managers to make more accurate decisions and deliver better service to customers.