Implementing Digital Twins of Smart Factories with Interval Algebra

This paper presents an interval algebra that can be used to create an analytic description of a smart factory. Such a description (recently termed a `digital twin' of the factory) is used to evaluate alternative manufacturing configurations as part of a search-based optimisation process. Several extensions are proposed to the interval algebra for specifying smart factory production line details. A number of real-life manufacturing scenarios are described, related to Wire-cut Electrical Discharge Machining. The experimental results show the applicability and scalability of the proposed method.