Editing of History is restricted for obvious reasons. There is however provision for unrestricted editing within a certain period after the date work was completed (not the date the data was entered).
This period is set by the administrator Home --> Maintenance --> Setup --> Utility Edit
Should History require editing after the pre-set unrestricted period, this would need to be undertaken by a user with a sufficient level of permissions.
Editing of History is undertaken from a History page. Depending on which screen the Historical error is found, by tapping on the relative error the following pop-ups will display to allow for access to the History screen and/or direct to the Edit screen.
All edits/changes are logged in an Audit Trail.