Screen oriented data flow analysis

A method for performing data flow analysis of computer code, comprising: providing computer code of a computer program having a plurality of user interface screens; dividing the computer code to a plurality of portions such that each one of the portions includes code for inducing at least one of loading and using one of the user interface screens; performing a variable usage analysis to detect which variables are at least one of calculated and used in each one of the portions; constructing a data dependence model defining dependencies among the portions based on the variable usage analysis; and identifying, for at least one of the portions and using the data dependence model, at least one unnecessary variable loaded in one of the user interface screens and not used in a respective portion and in a group of portions depending on the respective portion.