Zoë Stephenson is a Senior Software Engineer at Rapita Systems Ltd. Her responsibilities are mainly focused around provision of qualification information for customers in critical domains. She received her PhD from the University of York in 2002 and has worked on academic research projects with a number of industrial partners including Esterel, BAE Systems, Rolls-Royce, Goodrich Control Systems, Aero Engine Controls and Jaguar Landrover. For PROARTIS, Zoë is involved with management of tool support for the new analysis techniques being developed by the project. She is also the main contributor to the structure of certification arguments, providing a framework for validation evidence to help convince method user and regulators of the soundness of the proposed techniques.