1. The document discusses application development challenges for the Internet of Things (IoT), including heterogeneity of devices, large scale, lack of separation of concerns, and life-cycle issues.
2. It proposes a conceptual model that classifies IoT concepts and relates development concerns to promote reusability.
3. A multi-stage model-driven approach is presented using a set of modeling languages to abstract heterogeneity, scale, and support automation across development stages.