The JIS design was based upon the information requirements of six pilot jurisdictions in Oregon, California, Arizona, Kentucky, Florida, and New Jersey. The result is an online, defendant-based, 'subject-in-process' tracking system. Operational transactions include intake (defendant record initiation, medical check, booking record initiation, property record, preliminary classification, and housing assignment); pretrial release (bail-bonding and recognizance release screening and supervision); custody management transactions (classification and cell assignment, event scheduling and history, property and fund accounting, program assignment, incidents, visitors, time served, release date calculation); and diversion, probation, and parole. Besides programs for entering data and responding to online inquiries and indexed searches, JIS includes capabilities for document production, such as work-flow analysis reports. JIS contains most of the capabilities of PROMIS (Prosecutor's Management Information System), and can be tailored to incorporate special and relational edits, cyclic and initial modes, summary fields, and combined case and defendant tracking. Implementation planners should identify user groups, conduct a feasibility study, perform an information requirements analysis, and select a computer system. Further planning steps concern system security and user training. Tabular and graphic illustrations are provided.