Recently, Sensor/Actuator Networks have become an emergent technology for various application areas such as security and surveillance applications, traffic control, logistics, energy control in public and private buildings, etc. Designing and constructing new applications using these technologies remain, however, a challenging task. Indeed, finding the relevant sensors and actuators, and combining them in a proper way in order to achieve a specific goal is not an easy task and requires several skills from different stakeholders. Moreover, sensor environments are inherently highly dynamic. Furthermore, current applications are in general tightly coupled to the underlying infrastructure which hampers their reuse and flexibility to changes. In this paper, we present a process-oriented and service-based approach for supporting the development of adaptive sensor-based applications. Our approach decouples application logic from its implementation. A design-time model is first specified, as a flow of activities, which is then deployed in a particular environment. Decoupling the application logic from its implementation enables, on one hand, to foster the reuse at the application level and, on the other hand, to adapt the same application to different environments and situations. We propose also an activity recommendation technique to provide assistance to application designers by recommending to them activities that have been used in a similar compositional context. Our approach has been prototyped using service standards such as BPMN within the context of the VITRO European project and validated by several use cases