Critical to the successful design of fusion reactor components is the development of coupled simulation models, capable of conducting efficient whole system design optimisation and virtual component qualification, under conditions which cannot be readily tested. Additionally, successful lifetime monitoring and predictive maintenance of fusion components through diagnostic measurements will be limited due to restricted accessibility and operation in a harsh environment. There is therefore a need for a component digital twin, which combines data from the physical instrumentation with simulation to provide a platform for virtual testing but also enhanced and abundant diagnostics in ‘real-time’. CHIMERA (Combined Heating and Magnetic Research Apparatus) is a unique, multi-physics fusion component loading facility under construction at the UKAEA Yorkshire site. CHIMERA will be used as a testing platform to develop and validate the virtual test and digital twin capability. Initial efforts are focussed on the post-commissioning testing, where the first experimental data will come from, with models of the commissioning sample under test (CSUT) being developed. A systems simulation approach has been adopted covering hydraulic, thermal, electromagnetic, and mechanical domains. Each domain and section of the system are linked through fast-running surrogate models. This model forms the foundation for future developments to include probabilistic simulation, uncertainty quantification and real-time tracking alongside the physical asset. First, this paper will outline the overall strategy and roadmap towards realising the virtual test and digital twin capability. Secondly, the methods and techniques used in the initial CHIMERA-CSUT systems simulation within ANSYS Twin Builder will be described. Simulation results of the commissioning tests are presented, alongside quantification of performance and verification against higher order models, with particular focus on virtual diagnostics such as thermocouple and strain gauge outputs. Finally, the key challenges and next stages of research and development are summarised.