Overriding system attributes and function returns in a software subsystem

An approach is provided in which a request is received from a software module to retrieve a value stored in a pre-defined location. Prior to retrieving the value, an override tank is checked for a corresponding override value. When the override tank includes an override value, the override value in the override tank is provided to the software module. When the override tank fails to include a corresponding override value, an actual value is retrieved from a pre-defined storage location and provided to the software module. In one embodiment, the override value is an override system attribute value. In another embodiment, the override value is an override function return value.