Towards iteration by design: An interaction design concept for safety critical systems

Requirements of human-machine systems change over long product lifecycles. Anticipating those changes during the initial design is challenging. Once deployed the changing requirements demands a systematic evaluation of the human-machine system, otherwise inefficiencies and accidents can happen. The interaction design concept Iteration by Design introduces a fifth design phase to the user-centred design process of the ISO 9241-210 norm to close the open evaluation loop of safety critical systems with long lifecycles. The implications of Iteration by Design are discussed in the context of resilience engineering. A higher order adaptation regulation loop copes with the complexity of the human-machine system interaction design. The resilience principles drift reaction and human in the loop are utilized to adapt the system to the changing requirements. A design assistance system is proposed to inform a design team about required changes. Finally, adaptive instructional training could be interwoven with the design assistance system to sustain the adaptability of the human-machine system. The value of Iteration by Design as an extension for user-centred design is illustrated by the accident of the USS John S. McCain from 2017.