Offender Assessment System (OASys)

Ensuring that the public is protected is an essential pre-cursor to reducing re-offending and lies at the heart of Government’s Five-Year Plan for managing offenders. The National Offender Management Service regards ‘end-to-end’ management of offenders as its main tool for achieving this goal. This process is underpinned by the Offender Assessment System (OASys), which involves those given a prison sentence of twelve months or more, and has a number of objectives that can be summarised as follows:

  • Assess how likely an offender is to be re-convicted
  • Identify and classify offending related needs
  • Assess the risk of harm to self and others
  • Assist with management of the risk of harm
  • Facilitate the link between assessments, supervision and sentence plans
  • Indicate any need for further specialist assessments
  • Measure how an offender changes during the sentence

In practice the system gathers information on prisoners, including their offences and then gives them an OASys score under each of the following headings:

  1. Accommodation
  2. Education, training and employability
  3. Financial management and income
  4. Relationships
  5. Lifestyle and associates
  6. Drug misuse
  7. Alcohol misuse
  8. Emotional well-being
  9. Thinking and behaviour
  10. Attitudes
  11. Health & other considerations

The Risk Of Serious Harm Assessment that flows from the process covers such things as the risk of serious harm to others, especially children and to the individuals themselves, which includes suicide, self harm, vulnerability and the ability to coping in custody. Other risks cover factors such as risk of escape or absconding, control issues and breach of trust. Prisoners overall Risk of Serious Harm is then established under the following categories:

  • Low – No significant, current indicators of risk of harm.
  • Medium – there are identifiable indicators of risk of harm. The offender has the potential to cause harm but is unlikely to do so unless there is a change in circumstances, for example, failure to take medication, loss of accommodation, relationship breakdown, drug or alcohol misuse.
  • High – There are identifiable indicators of risk of harm. The potential event could happen at any time and the impact would be serious.
  • Very High – There is an imminent risk of harm. The potential event is more likely than not imminently and the impact would be serious.

For those offenders who have received a very high, high or medium rating in relation to risk of serious harm, risks to the individual and other risks, a management plan must be completed. The management of this group of offenders must be in line with the Prison Service Public Protection Standard and priority is given to these offenders for any relevant intervention programmes. However, the assessments are used to draw up a Sentence Plan for all prisoners. In most cases this will be completed within 8 weeks of sentencing and is then reviewed by assessors at appropriate points during the sentence. This is reviewed generally once a year but might occur earlier if there are triggers that necessitate a review. These include factors such as possible release on temporary license (ROTL), disciplinary reasons, especially if a possible change of risk is involved, or the need to develop a resettlement plan. Reviews can alter a prisoner’s OASys score, and the lowering of the score indicates that a prisoner is at a lower risk.

The OASys process is also used to look at the factors affecting social exclusion in line with the Seven Pathways model for identifying needs and planning interventions. This is part of the ‘end-to-end’ management of offenders being implemented by NOMS with the primary intention of reducing re-offending on release.