A description of those portions of the monitor, the JOSS system's supervisory unit, that produce accounting records for charging functions and that gather performance statistics descriptive of typical user operation, over-all system usage, and machine performance. Charges for JOSS usage are based on the product of machine time and core space required plus the product of space and time required for long-term storage of programs and data on the disc file. Charge units are accumulated during JOSS operation and recorded on magnetic tape. The reports produced from the tape records record charges and other characteristics of individual JOSS sessions and the total usage both by department number and by project number. Much of the code and storage in the JOSS system is devoted to recording the occurrence of events that will help determine the system's performance and its operating environment. Certain data are displayed each minute on the JOSS master console, and other more global data are recorded in memory and displayed every four hours. The four-hour summary is periodically reduced by a JOSS program to give profiles of both the system's over-all operation and of the characteristics of individual usage of the system. 69 pp. Bibliog.