Locking Logbooks

When an employee has completed a logbook and signed it, this should be locked in place. If we do a future edit on the logbook (via settings) to reflect a new year or date period. This retrospectively changes all completed logbooks that have been signed. It doesn't make sense in having to create duplicate versions of the same Logbook in order to avoid historical ones being changed.

I have attached screenshots:

Image Labelled 1 = Original Logbook signed on 31st May

Image Labelled 2 = Changed iHasco to LMS in the Logbook Settings, and this has now changed the original logbook still signed as 31st May.