The recommendations of the Stevens report, which were published this morning, are due to be enacted over the course of the next eight months.
Key among them is the suggestion that an internal investigation department would be established by the PSNI to investigate any allegations or suspicions of collusion and corruption.
In response to the finding that some police officers in the RUC colluded with loyalist paramilitaries, Sir John recommends that all senior investigating officers dealing with paramilitary murders should be vetted before they can access sensitive intelligence.
In addition, a full review of the training for all agent handlers is recommended, with particular emphasis on integrity issues and the keeping of records of all interviews.
He also recommends in relation to Covert Human Intelligence Sources (CHIS) - or undercover agents - that they should only be used to cover what the overview describes as "a proportionate coverage of the terrorist threat".
On an organisaitonal level, the recommendations foresee the establishment of a specialised, dedicated unit for the investigation of terrorist offences, under the control of an assistant chief constable who, in turn, would answer directly to the Chief Constable.
The role of this department would be reinforced by service level agreements between all department and external partner agencies to ensure that the boundaries between departments are not overstepped.
However, where it is suspected that someone within the police or army has been involved in a murder or other serious crime, the overview says that the senior office involved in the investigation should receive full co-operation from all departments.
Speaking at the publication of the overview and recommendations, Sir John Stevens, Commissioner of the Metropolitan Police Service, who was responsible for compiling the report, said its was "essential to the fight against terrorism here and elsewhere that [the] 21 recommendations were implemented in full".
He added: "I will be coming back with Her Majesty's Inspector of Constabulary next January to audit and see they have been enacted."
The recommendations draw on information uncovered by his three Enquiries carried out over the past 14 years.