Massively deployed wireless sensor and actuator networks, co-existing with RFID technology, can bring clear benefits to large-scale enterprise systems, by delegating parts of the business functionality closer to the point of action. However, a major impediment in the integration process is represented by the variety of customized platforms and proprietary technologies. In this article, we present a three-layer, service-oriented architecture that accommodates different sensor platforms and exposes their functionality in a uniform way to the business application. Our work is motivated by real business cases from the oil and gas industry. In our implementation, we use three sensor platforms (particle, muNode, and Sindrion) integrated through the universal plug and play (UPnP) standard and incorporated into an enterprise software system. The practical tests and application trials confirm the feasibility of our solution but also reveal a number of challenges to be taken into account when deploying wireless sensor and actuator networks at industrial sites.