The decision to release an inmate on parole rests with the Home Secretary who operates on advice from the local review committee of the prison and/or the parole board. In addition to using reports from authorities and others, decisionmakers in the parole unit of the Home Office use a prediction score. In general, about 50 percent of those considered are released on parole and usually are placed under supervision. Overall, the parole system is felt to be a powerful and positive influence within the prison system and to provide fairly effective controls on parolees during supervision. Factors contributing to the success of the system include comprehensive parole dossiers, a reliable and independent decisionmaking process, sensible and thorough release plans, and effective sanctions for violations. In addition, the system demands that inmates work for parole, and it is generally believed to fundamentally just. A new parole system, covering inmates with sentences under 2 years, may not prove as effective because it lacks some of these factors.