A system for dynamically integrating changes in the rules governing business operations into an application program that implements the rules in order to control business operations includes a dynamic business logic rule integrator (“DBLRI”) that essentially provides business logic rules to the application software as executable routines. The DBLRI presents to a user one or more graphical user interfaces (“GUIs”) through which the user writes functional-language expressions for the business logic rules. The respective GUIs correspond to various types of business logic rules, and provide to the user menus of associated functions, operators and parameters that are available for use. The set of parameters associated with a given GUI is dynamically updated, to correspond to changes in the underlying business logic rules. The user writes and/or edits the expressions for the respective business logic rules by selectively combining the available functions, operators and parameters. The DBLRI translates the functional expressions into executable routines by evaluating the corresponding expressions and producing associated executable parse trees or DLLs. The application software then calls the executable routines at appropriate times. The DBLRI operates also with a dynamically configurable database that provides various parameters required for the business logic rules as the rules are updated, added and/or revised.