1. A computer implemented method comprising: storing model metadata for each of a plurality of mathematical models; receiving data describing two sets of models, wherein each of the sets identify one or more models of the plurality of mathematical models, and wherein one of the sets comprises a transition-from set and one of the sets comprises a transition-to set, wherein, when executed, each of the models in each of the sets is configured to process sets of data, each of the sets of data being associated with a data processing start date; receiving data describing a launch date for commencing a transition from executing the one or more models in the transition-from set to executing the one or more models in the transition-to set; receiving data describing a transition period of time for the transition; executing, using a computer processor, the one or more models in the transition-from set on the sets of data that are associated with a data processing start date that is within the transition period of time and executing the one or more models in the transition-to set on sets of data that are associated with a data processing start date that is after the transition period of time and, after the transition period of time, executing the models in the transition-to set on all of the sets of data; combining, using the computer processor, an output of the execution of the one or more models in the transition-from set with an output of the execution of the one or more models in the transition-to set; and storing the output in a database.