Wireless sensor networks rapidly invaded several application domains. The nodes that make up these networks are electronic devices designed and sized to meet the needs of surveillance, data collection and transport, communication, etc. However, Operation and design of the wireless sensor network systems require reliable and efficient simulation tools before actual implementation of the application. In this paper an analysis of the performance of the modeling phase of the network and simulation tools was presented as a synthesis to evaluate the performance of the systems of a wireless sensor network.