Zohra Sbaï, International Journal of Advanced Trends in Computer Science and Engineering, 10(2), March - April 2021, 728 - 735 728 ABSTRACT Industrial Internet of Things (IIoT) services composition rely on composing existing IoT services in industrial context in order to obtain an overall service with added value. The composite service’s behavior is extremely influenced by the time, availability, and accuracy of the unitary services. Thus, it is extremely important to guarantee a provision of IIoT services as expected during the modeling phase. For this, we lie on formal verification to check all the possible scenarios before to pass through IIoT services provision. We propose first to model each process involved in the composition by open Time Petri Nets. These nets offer interface places for the purpose of process communication with the other processes. Then the composition of open Time Petri Nets is guaranteed via superimposing the interface places and thus obtaining a Time Petri Net modeling the composite process. Finally, control and operational behaviors of IIoT services composition formally checked after being specified in an expressive fragment of TCTL temporal logic. Key words: IIoT, services composition, Time Petri Nets, model checking. 1. INTRODUCTION IoT services form a novel yet important concept generated by the growing need of smart objects facilitating daily lives. They may represent customized, pervasive and cyber physical services that are in general designed according to static environment and typical IoT entities that interact together. Thus, in these solutions, services provisioning is measured according to specific user need, current position, sensors, etc. The challenge now is to guarantee a dynamic provision of IoT services since these latter may run and stop according to a certain space and time under certain conditions. So to ensure their reliability, IoT services need to be designed with considerations of self-configuration and self-optimization. This will so far help to reduce the smart objects damage and to enlarge their life durations and to gain a maximum productivity. Such issues are even more important in case of industrial internet of things (IIoT). One major issue is that it is extremely important to guarantee a provision of IIoT services as expected during the modeling phase. For this, we lie on formal verification to check all the possible scenarios before to pass through IIoT services provision. IIoT services composition rely on composing existing IoT services in industrial context in order to obtain an overall service with added value to the end user. The composite service’s behavior is extremely influenced by the time, availability, and accuracy of the unitary services. For example, in a manufacturing process, it is important to monitor the production lines starting from the treatment of raw material to the packaging, transport, and tracking of the final products. As another example, in emergency medical care, it is extremely important to guarantee the accuracy and the respect of constraints in the processes involved in the treating of an emergency case for example such as a person who had an accident or a patient in a hospital whose state is aggravated. In these contexts, as well as more other sophisticated contexts, the composition of existing IIoT services may be guaranteed via the interaction of different services. This interaction may be assured by allowing communication between the different partners of the composition. Communication here may cover messages exchange or even resources sharing such as IoT devices, robots, computers, etc. Since many partners are invited to communicate together and to operate collectively in order to achieve common goals, a sound control and operational behavior of the overall process should be ensured. An operational behavior refers to a Formal Verification of Control and Operational Behaviors in Industrial Internet of Things Services Composition Zohra Sbaï Computer Science Department, College of Computer Engineering and Sciences, Prince Sattam Bin Abdulaziz University, Saudi Arabia National Engineering School of Tunis, Tunis El Manar University, Tunisia Email: z.sbai@psau.edu.sa ISSN 2278-3091 Volume 10, No.2, March - April 2021 International Journal of Advanced Trends in Computer Science and Engineering Available Online at http://www.warse.org/IJATCSE/static/pdf/file/ijatcse381022021.pdf https://doi.org/10.30534/ijatcse/2021/381022021