The Rehab Group has appointed independent management consultant Dr Eddie Molloy to conduct a review of the organisation in the wake of its recent controversies.
In a letter to staff, the board says the group's response to political and public demands for information has been inadequate.
It says that the board has not exercised strict and appropriate oversight of certain issues that have come to public attention in recent weeks.
It also says the board's earlier response was partly due to legal constraints.
The review will look at governance and structures and how it conducts its affairs.
Changes to the Board may also follow.
Chairman of the Rehab Group Board Brian Kerr said that the aim was to rebuild the reputation, staff morale and effectiveness of the organisation.
It also wants to rebuild public trust.
Dr Molloy has 35 years of experience in the public, private and charity sectors, is chairman of Mental Health Reform and the Public Appointments Service.
The letter to Rehab Group staff says the reputation of the group has been "seriously damaged".
It says that for legal reasons it could not disclose information about the terms and conditions of senior people.
The business and governance structure of the organisation was also inadequate to manage a very challenging and changing situation.
The letter says that it also needs to recover the confidence of the Government and colleagues in the charity sector, who have suffered because of the fall-out over the current controversy.
The review will look at how people are paid across the group, so that Rehab "not only meets but exceeds reasonable public expectations and regulatory requirements".
The review will also involve engagement with staff but it will not be an examination into the operations of any individual unit.
PAC welcomes review
The Public Accounts Committee has welcomed the decision of Rehab to appoint an independent consultant to conduct a root and branch review of governance at the disability support organisation.
PAC chairman John McGuinness said it was an important" first step" in initiating change at Rehab.
The Fianna Fáil TD said the issue will also be dealt with at the PAC meeting with Rehab on Thursday.
Mr McGuinness said the committee had still not heard from former CEOs Angela Kerins and Frank Flannery regarding their attendance but expected them to appear.
Rehab brought up during Leaders' Questions
Fianna Fáil leader Micheál Martin asked Taoiseach Enda Kenny about the operation of Rehab during Leaders’ Questions.
He said there is a necessity for former CEO's Angela Kerins and Frank Flannery to appear before the PAC.
He said there are issues around the payment for lobbying Government departments and that Mr Flannery enjoyed unrivalled access to the Fine Gael.
He asked if the Taoiseach was aware that Mr Flannery was being paid by Rehab to lobby government departments.
He also said that the Rehab case is fairly unique as Fine Gael have supplied Frank Flannery with a pass into Leinster House and so on.
He said he thinks it is wrong for organisations like Rehab to pay people to lobby.
The Taoiseach said it is a question for Rehab to answer if they paid anyone to lobby.
He said that he does not believe that charitable organisations should pay people to lobby.
He said that he does not have information on payments and said that the Government is bringing in new lobbying legislation.