In industrial plants, there is a mix of devices with different security features and capabilities. If there is a mix of devices with various degree of security levels, then this will create independent islands in a network with similar levels of security features. However, the industrial plant is interconnected for the purpose of reducing cost of monitoring with a centralized control center. Therefore, the different islands also need to communicate with each other to improve the asset management efficiency in a plant. In this work we aim to focus on the trustworthiness assessment of devices in industrial plant networks in term of node value. We study the behavior of industrial plant networks when devices with various degrees of security features communicate. We aim to identify network properties which influence the overall network behavior. From the study, we have found that the communication path, the order of different communication paths and the number of specific types of nodes affect the final trustworthiness of devices in the network.