6.22. A key requirement for decision making, and possibly one of the most difficult to justify, will relate to the sufficiency of site information. Ultimately, the decision on when the site characterization is complete will need to be based on confirmation that its objectives have been met in terms of the quantity and quality of data necessary to support safety assessments, disposal design and environmental impact assessments or for providing additional confidence in understanding the system and processes. As part of the site investigations, the quantity and quality of data to support safety assessments and the post-closure safety case will be considered when the value of any additional data collected will not significantly impact on safety. For example, sensitivity studies may indicate that key data uncertainties are manageable, that calculated dose and risks remain within the bounds of regulatory limits, constraints or a target and that any further collection of data would not increase confidence in the safety case. This may be a useful basis for the decision regarding when site investigations for safety assessments may be considered complete (although it is noted that continued monitoring may be of value).