HM Prison and Probation Service

Combines a manual assessment covering offence analysis, accommodation, education and employment, finances, relationships, lifestyle, drugs, alcohol, emotional wellbeing, thinking and behaviour, attitudes and health, with statistical calculators. OGRS 3 uses gender, previous sanctions, age at current conviction, age at first sanction and offence type to output a percentage likelihood of proven reoffending at one and two years; OGP and OVP combine that score with questionnaire sub-scores for general and violent reoffending predictions.

Used on more than 1,300 people per day (see the Freedom of Information figures below), and in use since 2001 with rollout across the prison and probation system between 2001 and 2005. Outputs feed sentence planning, prison categorisation and supervision decisions. A replacement, Assess Risks Needs and Strengths, is being built in-house by Ministry of Justice Digital. Concerns about accuracy and discrimination have been raised by Statewatch and in trade reporting.

Update, November 2026. An HM Prison and Probation Service Freedom of Information response dated 28 February 2025 (request 250107008, signed by the Head of Risk and Domestic Abuse Policy), read directly for this review, states that 7,090,636 OASys assessments were held at 12 January 2025, including those in progress, and that 9,420 assessments were completed in the week 6 to 12 January 2025, which is roughly 1,346 a day on the reviewer's arithmetic, and 476,474 over 12 months. It says the Assess Risks, Needs and Strengths project is developing a new digital tool to replace OASys, that a prototype was being piloted from December 2024 and that national rollout was planned for 2026, and it withholds details of the replacement under section 35(1)(a) of the Freedom of Information Act. The response does not mention OGRS, OGP, OVP or validity by ethnicity. No source found confirms whether the replacement has gone live, so OASys remains recorded as operational.