According to Article 4, Statute of Open Prisons:

The Agency of Corrections, Ministry of Justice shall select those prisoners that meet the following requirements from all prisons as the prisoners for the open prison:
1.An inmate who has served more than two (2) months;
2.An inmate whose sentence is not more than seven (7) years ,or whose sentence is over seven (7) years but less than fifteen (15) years, if upward three grade under the Progressive Treatment System; or whose sentence is not less than fifteen (15) years but upward two grade under the Progressive Treatment System. A lifer who upward first grade under the Progressive Treatment System.
3.One with evidence of repentance and physically and mentally healthy for outside labor operations.

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Prisoners fall under the following conditions may not be selected:
1.An inmate who has committed the crimes prescribed in Article 161 of the Criminal Code.
2.An inmate who has committed the crimes prescribed in Narcotics Hazard Prevention Act.
3.A recidivist.However, all the previous case has been punished by imprisonment of not up to six months, unsealed.
4.An inmate whose parole is revoked due to committing a crime.
5.An inmate who has the rehabilitative disposition to be executed.
6.An inmate who has committed the crimes prescribed in Article 2, Paragraph 1 of Sexual Assault Crime Prevention Act or domestic violence offense referred to in Article 2, Subparagraph 2 of Domestic Violence Prevention Act.

The work-flow, procedures, conditions, examination guidelines, and other binding matters for notification shall be prescribed by the Ministry of Justice.

Source: https://law.moj.gov.tw/ENG/LawClass/LawSearchContent.aspx?pcode=I0040013&norge=4