Under UK charity rules, trustees can be in place for nine years or more.
It followed criticism of the boards handling of thebullying allegations.
In November, Deadlineuncovered bullying and misconduct allegationsagainst ArtsEd principal Julie Spencer.
ArtsEd graduation ceremony with principal Julie Spencer (front row, fifth from right).ArtsEd/YouTube
A terms of reference was published last week, revealing that the deadline for evidence submissions is January 22.
Interviews with witnesses will then take place over the next month.
ArtsEd plans to issue recommendations and a public statement by March 29.
Spencer is on medical leave and will not return to work while the investigation is ongoing.
Lloyd Webber is ArtsEds president and his foundation has donated millions of pounds to the school.
He has not commented on the allegations.
ArtsEds patrons includeThe Crownstar Lesley Manville.
