4.7. As outlined in para. 2.10, a disposal facility is developed in a step by step manner. The step by step approach adopted should enable:@@- Systematic collection and assessment of the necessary scientific and technical data;@@- Evaluation of possible sites; @@- Development of disposal concepts;@@- Iterative studies for design and safety assessment with progressively improving data; @@- Incorporation of comments from technical and regulatory reviews; @@- Consultation with the public for specific decision points;@@- Political involvement.@@The exact process followed should be determined on the basis of the type of facility and national practices.