TISSEA: A Framework for Testing IoT Systems Based on Technical Software Engineering Aspects

Internet of Things (IoT) systems refer to interconnected systems of devices that collect, process, and exchange data. As IoT adoption continues to grow, ensuring effective testing is of paramount importance. However, testing IoT systems remains a challenge, particularly for software engineers, due to the need to test aspects beyond their primary area of expertise (e.g., security, sensor calibration, and connectivity). Testing aspects refer to any concept or concern that should be considered when testing a given system. While several frameworks for testing exist that focus on generic aspects of IoT systems, there is no dedicated framework for testing technical software engineering (SE) aspects of IoT systems. To address this gap, we propose and evaluate TISSEA, a framework to guide software engineers to test the technical SE aspects of IoT systems. We constructed TISSEA by identifying all possible technical SE aspects from published taxonomies for IoT systems testing. Further, we mapped each aspect to the granularity of testing at each layer of the IoT system. We finally mapped each aspect with test orchestration strategies, test input artifacts, and execution strategies. We evaluated the TISSEA by surveying 22 professionals and conducting two case studies: 1) event logging and handling testing and 2) data integrity testing. The survey results show that professionals agreed with the proposed technical SE aspects for testing the device and application layers. However, the aspects proposed for testing the gateway and cloud layers still require further investigation. Results of the case studies indicate a gap between expected and captured log events. Regarding event handling, we found that some of the events reported by the system as successfully handled may include unhandled events that cannot be identified when relying on a single orchestration strategy. Regarding data integrity testing, we found that data can be altered at any node at any layer of the IoT system. However, accessing the original data allows the detection of modifications made to it at each node. Overall evaluation of TISSEA shows strong agreement with practitioners, and it could be useful to test technical SE aspects of IoT systems.