THESE MODEL DESCRIPTIONS ARE DESIGNED TO BE ADEQUATE FOR CRIMINAL JUSTICE PLANNERS AND POLICYMAKERS TO DETERMINE WHETHER AN APPROPRIATE MODEL ALREADY EXISTS FOR HANDLING A PARTICULAR PROBLEM, AND, IF SO, WHICH ONE WOULD BEST MEET THEIR NEEDS. IN ADDITION TO DESCRIBING THE MODELS, THIS STUDY REVIEWED THE CIRCUMSTANCES UNDER WHICH CRIMINAL JUSTICE MODELS ARE OR ARE NOT IMPLEMENTED BY OPERATING AND PLANNING AGENCIES. IN GENERAL, MODELS HAVE FAILED TO ACHIEVE THE LEVEL OF USE FOR POLICY DECISIONS THAT WAS INTENDED BY THE MODEL BUILDERS AND THOSE WHO FUNDED THEM. THE FINDINGS CONCERNING THE CAUSES OF IMPLEMENTATION SUCCESSES AND FAILURES INDICATE HOW FEDERAL RESEARCH ADMINISTRATORS MIGHT IMPROVE THE QUALITY AND USEFULNESS OF MODELS IN THE FUTURE. THE TEXT DESCRIBES OVERALL MODELS OF THE CRIMINAL JUSTICE SYSTEM AS WELL AS MORE SPECIFIC POLICE, COURTS, AND CORRECTIONS MODELS. INFORMATION PROVIDED FOR EACH MODEL GENERALLY INCLUDES THE HISTORY, POLICY ISSUES ADDRESSED, STRUCTURE, DATA BASE REQUIRED, OUTPUT, COST AND COMPUTER REQUIREMENTS, VALIDATION, IMPLEMENTATION AND IMPACT, LIMITATIONS, TRANSFERABILITY, AND DOCUMENTATION. SOME OF THE OVERALL CRIMINAL JUSTICE MODELS DESCRIBED ARE JUSSIM (CRIMINAL JUSTICE SIMULATION), CANJUS (CANADIAN APPLICATION OF JUSSIM), (PHILADELPHIA JUSTICE IMPROVEMENT MODEL), AND DOTSIM (DYNAMIC OFFENDER TRACKING SIMULATION). THE POLICE MODELS ADDRESS THE PROBLEMS OF POLICE MANPOWER DEPLOYMENT ESPECIALLY AS THEY IMPACT ON POLICE PATROL PROCEDURES. COURT MODELS INCLUDE CANCOURT (CANADIAN COURT SIMULATION MODEL), LEADICS (LAWENGINEERING ANALYSIS OF DELAY IN COURT SYSTEMS), AND A JUROR MANAGEMENT MODEL. THE CORRECTIONS MODEL DESCRIBED IS FCSM (FEDERAL CORRECTION SIMULATION MODEL). THE APPENDIX CONTAINS BRIEF DESCRIPTIONS OF THE 46 MODELS CONSIDERED (FROM WHICH THE TWENTY WERE CHOSEN FOR DETAILED DESCRIPTIONS) AND LISTS DOCUMENTATION RELATED TO EACH MODEL; A BIBLIOGRAPHY CONTAINING 195 ENTRIES IS PROVIDED; AND, THE OVERVIEW REPORT IS PRECEDED BY A NONTECHNICAL EXECUTIVE SUMMARY INTENDED FOR ADMINISTRATORS OF CRIMINAL JUSTICE PLANNING AGENCIES. (AUTHOR ABSTRACT MODIFIED) (SNI ABSTRACT)