A tailored add-on component for a released software product having internal and released development objects. The released development objects are designed for external use, such as end-user customization. The internal development objects are designed for use within the released software product, with no access from outside components. The tailored add-on component adds a functional application that makes calls to both released and internal objects. Access to internal objects is made while maintaining stability by confining internal object calls to a single adaptation component within the add-on, while also implementing an interface for the objects of the software product that are used by the add-on. The interface includes a function to freeze objects that are in the interface, and a set of automatic test components to identify changes in the objects that are in the interface.