6.27. It is also possible to use maturity as a guide to determine the amount of effort that should be expended on the assessment or review of a particular disposal facility, component of the disposal system, or process influencing the performance of the disposal system. In this sense, consideration of maturity may refer to: (i) the use of well established practices, procedures and designs; (ii) the availability of knowledge of the operational performance of similar facilities or practices (and the associated uncertainties); and (iii) the availability of experienced manufacturers, constructors and those conducting safety assessment. In general, the necessary depth of assessment and review efforts will be reduced with increasing levels of maturity. While the maturity criterion can be applied to disposal facilities for radioactive waste, it has to be recognized that data on the actual long term performance of disposal facilities are not available. The limited number of facilities and the uniqueness of each disposal system also have to be recognized.