Modeling of Sewerage System Linking UML, Automata and TLA+

Internet of things (IoT) means interconnection of heterogeneous nodes implemented in order to sense input data, interpretation, processing and output within a network. The smart environment is transformed by embedding heterogeneous devices into real scenarios. In the existing work, IoT infrastructure is rarely implemented in real time scenarios because of lack of knowledge, infrastructure handling and lack of resources. The researchers have proposed many techniques to implement IoT based smart city but these do not implement the above issues effectively. In this paper, we have focused on the IoT, UML, automata and Temporal Logic of Actions (TLA+) based sewerage system of a smart city. Our proposed sewerage system is developed by UML activity diagram and then converted into Non-deterministic Finite Automata (NFA) in which a junction is represented by a state and flow of water is represented as a transition. A state of system is defined as safe if flow of wastage from one junction to another has a safe path predicting behavior of water. The proposed UML and automata-based models are then transformed into a formal model using TLA+ which has an effective model checking capability. The proof of correctness of the proposed model is provided by TLC which is a model checking facility available in TLA+ toolbox.