1. A computer program product for imputing a missing value for each of one or more predictor variables, the computer program product comprising: a computer readable storage medium having computer readable program code embodied therein, the computer readable program code comprising: computer readable program code, when executed by a processor of a computer, configured to perform: receiving data from one or more data sources; for each of the one or more predictor variables, performing: building an imputation model based on information of a target variable; determining a type of imputation model to construct based on the one or more data sources, a measurement level of the predictor variable, and a measurement level of the target variable; and constructing the determined type of imputation model using basic statistics of the predictor variable and the target variable; and imputing the missing value for each of the one or more predictor variables using the data from the one or more data sources and one or more built imputation models to generate a completed data set.