4.76. The safety case should provide a synthesis of the available evidence, arguments and analyses. These should explain how relevant data and information have been considered, how models have been tested, and how a rational and systematic assessment procedure has been followed. The safety case should also acknowledge any limitations of currently available evidence, arguments and analyses, and should highlight the principal grounds on which a judgement has been made that the planning and development of the disposal system should nevertheless be continued. The safety case should include the approach by which any open questions and uncertainties with the potential to undermine safety will be addressed and managed. If the evidence, arguments and analyses do not provide sufficient confidence to support a positive decision, then the safety case, the facility design or even the disposal concept may need to be revised.