As the Wireless sensor/actuator networks (WSNs) started to be deployed in enterprise scenarios, the need of integration of WSN applications with enterprise business processes has emerged. Creation of the WSN applications in enterprises, however, requires much low-level programming, and this causes the loss of focus on the high level goals. Therefore a model-driven approach is needed. As Business Process Model and Notation (BPMN) is the de-facto standard of modeling business processes, it is suitable for companies to use BPMN for the model-driven approach. In this work, first we analyze the WSN properties, which distinguish them from traditional IT systems. Thereafter, we analyze the general properties of BPMN which need to be preserved to keep the common understanding that BPMN brings. As a result, we end up with some properties that are relevant with modeling WSN processes in BPMN. From these properties, we derive the requirements for modeling WSNs and propose some extensions to standard BPMN. These extensions include a new type of task, a new type of pool and a new grouping structure to set performance goals of the corresponding WSN. Afterwards, we analyze the current state of art to compare our approach with other possible approaches. Specifically, we compare our approach with standard BPMN, BPM4People extensions with respect to requirements and show that why our proposals provide a more comprehensive and suitable approach.