Periodic reassessment means looking again at things which are taken for granted, things which seem beyond doubt. Periodic reassessment means challenging all assumptions. It is not a matter of reassessing something because there is a need to reassess it; there may be no need at all. It is a matter of reassessing something simply because it is there and has not been assessed for a long time. It is a deliberate and quite unjustified attempt to look at things in a new way.