4.11. When developing the safety case, the needs of the key parties that will review, use and approve the safety case (e.g. government, the regulatory body and interested parties) should be identified and should be well understood; such needs will depend on the local and national situation. The safety case, including supporting safety assessment, is the responsibility of the facility operator, and it will need to be presented in a manner that meets the needs of the different interested parties. As far as possible, prior agreement should be achieved through communication with those parties, on what is to be included, assessed and calculated, as appropriate for each step of facility development and for the relative level of hazard associated with the facility. For example, the expectations of interested parties with regard to presentation and interpretation of the results of safety assessment may increase as licensing decision points are approached.