In this paper we consider the modelling and simulation of open quantum systems from a device engineering perspective. We derive master equations at different levels of approximation for a Superconducting Quantum Interference Device (SQUID) ring coupled to an ohmic bath. We demonstrate that the master equations we consider produce decoherences that are qualitatively and quantitativly dependent on both the level of approximation and the ring's external flux bias. We discuss the issues raised when seeking to obtain Lindbladian dissipation and show, in this case, that the external flux (which may be considered to be a control variable in some applications) is not confined to the Hamiltonian, as often assumed in quantum control, but also appears in the Lindblad terms.

Through case study analysis of physicists working in quantum systems, we establish that knowledge of Systems Engineering (SE) will benefit scientists by ensuring that experimental apparatus is robust and fully meets the experiment requirements. We suggest a paradigm shift in the training of early career research scientists to ensure they have a strong appreciation of the systems approach and experience of applying SE techniques. Two case studies were used: the first was a detailed analysis of increasing levels of SE in the development of a 3D-printer for fabricating superconducting nano-circuitry. Applying SE techniques improved record keeping, reduced the risk of failure modes and took better account of future development through which scientific discovery may be exploited in practical devices. The second case study focused on a group of 30 quantum physics PhD students undertaking a short-course in basic SE, and used their opinions to check and add confidence to the findings of the first case study. A variety of tools were used in both studies and, in both cases, the Functional Failure Means Effects Analysis (FFMEA) technique was considered to be most useful. Recommendations are made for the future training of early career scientists to include some light-weight Systems Engineering.

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