Process safety and risk management remain a significant challenge for the process and manufacturing industries. Digital systems have been applied over many decades to assist in process safety management throughout the lifecycle of a process plant. There has been much hype in recent years regarding Industry 4.0, digitalization and digital twins regarding the transformative potential that exists within these technologies to improve operational performance and reduce process safety accidents. In this article, a fundamental systems thinking approach is applied to the implementation of the digital twin within the process industries. The importance of having a standardized language and ontology, such as ISO15926, enables the use of reasoning engines and the ability to interconnect models and systems across the process and product lifecycle. We discuss use-cases and forms of the digital twin to improve safety within the process industries. A specific focus shows how an operator training simulator and its embedded dynamic models are applied within this environment. The article concludes with a summary of process safety related opportunities and threats associated with the application of digitalized dynamic models in industry. (C) 2019 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.