A framework for object registration, and in particular for registering and executing calculation models and business rules, is described herein. In one embodiment, metadata definitions and input/output Application Program Interfaces (APIs) define uniform conventions that, when followed by a customized calculation model or business rule, allow transparent execution of pre-defined as well as customized calculation models and business rules. In one embodiment, a customized calculation model is registered with a stored procedure and a metadata table. In another embodiment, business rules are registered with a stored procedure and type information. By following the uniform conventions, initial processing is enabled with pre-defined calculation models or business rules, while subsequent processing is seamlessly enabled with customized calculation models or business rules.