IN GENERAL, THE UNIT MANAGEMENT SYSTEM SUBDIVIDES AN INSTITUTIONAL POPULATION INTO GROUPS OF APPROXIMATELY 100 INMATES WHO RESIDE IN COMMON LIVING AREAS. ATTACHED TO EACH UNIT IS A STAFF CONSISTING OF A UNIT MANAGER, A PSYCHOLOGIST, ONE OR TWO CASE MANAGERS, TWO OR THREE CORRECTIONAL COUNSELORS, AND CUSTODIAL OFFICERS. BENEFITS ARE THE CLOSE CONTACT BETWEEN STAFF AND INMATES, BETTER DELIVERY OR PROGRAM PACKAGES, QUICKER PROBLEM IDENTIFICATION AND SOLUTION, AND PERSONALIZATION OF SERVICES. A HISTORY OF THIS STRATEGY OF PRISON MANAGEMENT IS PRESENTED, WITH PARTICULAR ATTENTION TO THE PLANS DEVISED AND IMPLEMENTATION STEPS TAKEN AT THE FEDERAL PRISON IN LEWISBURG, PA. THE IMPETUS FOR THE DEVELOPMENT OF THE UNIT MANAGEMENT SYSTEM AT LEWISBURG CAME FROM THE REPORT OF A BOARD OF INQUIRY IN 1976, FOLLOWING TYPES OF UNITS: (1) DRUG ABUSE PROGRAM, (2) ADMISSION AND ORIENTATION, (3) TWO UNITS FOR INMATES WORKING IN INDUSTRIES, AND (4) THREE 'MANAGEMENT' UNITS. THE DRUG ABUSE PROGRAMS UNIT AND THE INDUSTRIES UNITS ARE VOLUNTARY, BASED ON INTEREST AND MOTIVATION AND CHARACTERIZED BY PREFERRED QUARTERS TO PROVIDE AN INCENTIVE FOR INMATES. INMATES ARE ASSIGNED TO 'MANAGEMENT' UNITS ACCORDING TO PERSONALITY DIAGNOSES CONDUCTED DURING THE ORIENTATION AND ASSESSMENT PERIOD WITH THE AIM OF SEPARATING INMATES WHOSE PERSONALITY INTERACTIONS WOULD TEND TOWARD CONFLICT AND DISRUPTION. STAFF ASSIGNMENTS TO EACH UNIT ARE DISCUSSED. THE IMPLEMENTATION OF THE PLAN PROCEEDED IN A SEQUENTIAL FASHION, WITH INMATES AND STAFF RECEIVING THOROUGH BACKGROUND AND PROCEDURAL INFORMATION PRIOR TO EACH STEP. FOLLOWING THE ESTABLISHMENT OF THE UNIT MANAGEMENT SYSTEM, THE CLIMATE OF THE PRISON HAS BEEN OBSERVED TO CHANGE FROM ONE OF TENSION AND VIOLENT EXCHANGES BETWEEN INMATES AND STAFF TO ONE OF RELATIVE HARMONY AND SAFETY. A BRIEF LIST OF REFERENCES IS PROVIDED.