1. A computer system for performing risk and exposure calculations for an institution based upon stored rules and data, the computer system comprising: a management information data base for storing management data; a host computer; program means for performing risk and exposure calculations using the on said host computer according to rules stored as objects in a relational data base, said program means including, event processing means for responding to external and internal events, and interfacing means having predetermined seminal keys for receiving said management information data from said management information data base and for receiving market information data from a market information data source for use in said risk and exposure calculations; rule presentation means for displaying rules stored in said relational data base in a presentation format to a user, and for allowing the user to modify existing rules and create new rules using object operators; and rule translation means for translating rules from the presentation format to a table form for storage in said relational data base as an object.