IMPACT ANALYSIS

Methods, systems, and apparatus, including computer programs encoded on computer storage media, for impact analysis. One of the methods includes receiving information about at least two logical data sets, the information identifying, for each logical data set, a field in that logical data set and format information about that field. The method includes receiving information about a transformation identifying a first logical dataset from which the transformation is to receive data and a second logical data set to which the transformed data is provided. The method includes receiving one or more proposed changes to at least one of the fields. The method includes analyzing the proposed changes based on information about the transformation and information about the first logical data set and the second logical data set. The method includes calculating metrics of the proposed change based on the analysis. The method also includes storing information about the metrics.