1. A non-transitory computer-readable medium storing one or more computer executable instructions, the instructions comprising: one or more instructions that, when executed by a processor, cause the processor to: access a model, the model including a parameter or a signal, the parameter or the signal operating on data, the data being stored in an external data source that is independent of the model; generate a data object, at least in part, by loading information from the external data source, the data object: comprising a custom attribute for use in affecting a behavior of an operation performed by the model with respect to the data, the custom attribute having an assigned value; propagate the custom attribute to the model to define an aspect of the parameter or an aspect of the signal; and perform the operation by operating on the data object using a block in the model, the operating: affecting an interpretation of the data operated on by the model, and being based on the assigned value for the custom attribute of the parameter or the signal.