ABSTRACT
Industry 4.0 represents a trend in manufacturing which includes cyber-physical systems, the Internet of things, cloud computing and cognitive computing. Cyber-Physical Systems (CPS) refers to smart systems that include engineered interacting networks of physical and computational components. The term digital twin refers to a digital replica of physical assets, processes and systems that can be used in real time for control and decision purposes. The digital twin representation is seen as a prerequisite for effective synchronization of operation and maintenance within the manufacturing industry as well as in other industries. The relation between production plans and activities and actual production can to some extent be described by deterministic. The relation between maintenance plans and activities and the production system availability on the other and requires probabilistic representation. The term stochastic digital twin is therefore introduced. An ambition of Industry 4.0 is to support real-time processing whenever possible. This paper discusses elements of Industry 4.0. A case study is provided to demonstrate these terms and challenges to the mathematical modelling required for optimal synchronization of operation and maintenance.
