Abstract: In one embodiment, data is exchanged between a modeling application and an external application. A user initiates an export of model data from the modeling application, where the model data is descriptive of a model maintained in the modeling application. An export map is generated that captures an indication of each object in the model at the point in time of export of the model. Model data is passed to the external application. Subsequently, modified model data is received from the external application. The modified model data is compared with the export map to detect external modifications made by the external application. Limited portions of the model in the modeling application are updated to reflect the external modification, while intact portions of the model for which external modifications have not been detected are left intact.