Digital Twin for Legacy Systems: Simulation Model Testing and Validation

In this paper, an approach to incorporate a digitaltwin for legacy production systems is presented. Hardware-in-the-loop setups are routinely used by manufacturing companiesto carry out virtual commissioning. However, manufacturingcompanies having online legacy production systems are stillstruggling to incorporate a digital twin due to the absence ofverified and validated simulation models. Companies that usevirtual commissioning as a part of their engineering tool chain,usually perform offline verification of the simulation model.This approach is typically based on visual inspection and is atedious task as each aspect of the model has to be visuallyvalidated. For legacy systems, only assessing the behaviorvisually in the absence of updated documents can result in anincorrect simulation model, i.e. simulating incorrect behaviorwith respect to the specification. Due to this, such simulationmodels cannot be incorporated in the engineering tool chain,as the simulated results can lead to improper decisions and caneven cause equipment damage. This paper presents a platformand an approach, based on model-based testing, that is a firststep for manufacturing companies to incorporate a validatedsimulation model for existing online production systems thatwill serve as a digital twin