Digital Twin in Water Supply Systems to Industry 4.0: The Holonic Production Unit

Industry 4.0 (I4.0) and Digital Twin (DT) bring together new disruptive technologies, increasing manufacturing productivity. Indeed, the control of production processes is fast becoming a key driver for smart manufacturing operations based on 14.0 and DT. In this connection, intelligent control such as the Holonic Manufacturing Systems (HMS) generates distributed or semi-heterarchical architectures to improve both global efficiency and manufacturing operations' reactiveness. Still, previous studies and HMS applications often have not dealt with continuous production processes, such as water treatment applications, because of the complexity of continuous production (a single fault can degrade extensively and can even cause a breakdown of production). This work describes a HMS architecture applied to continuous systems, based on Holonic Production Units (HPU). This unit's cognitive model allows building a DT of the unit employing a hybrid dynamic system. This HMS detects events within the environment through a DT, evaluating various courses of action, and changing the parameters aligned to a mission. The DT was created by a simulated model of a water supply system, considering three scenarios: normal condition and two disrupted scenarios (the unexpected increase of demand and water quality degradation). The experiments apply agent-based modelling software to simulate the communication and decision-making features of the HPU. The results suggest that the construction of a holarchy with heterogeneous holons is potentially able to fulfil I4.0 requirements by DT of a WSS.