A method and system for analysing software to estimate the cost of production, development and maintenance of computer applications. Unlike previous proposals for such analysis, where the primary measured parameters are the numbers of lines of code and function points, the inventive method identifies high complexity software segments arising from specific discontinuities in execution of the program, ie points at which the program has to, in effect, make decisions. These items are assigned complexity indices which may be summed to give an overall complexity value for the program or the indices may be displayed as a histogram showing the complexity distribution of the program.