Effort estimation for program comprehension

The study presents an experience of deriving an econometric model for software comprehension; this process is necessary for the renovation of existing software systems. The model uses data on the process and products. The aim of the econometric model is to minimize the risks when forecasting the budget and time needed to carry out the project. After having obtained the basic model, the correction factors which could reduce the risk or error of the forecast are considered. In particular, one factor, the suitability of the tool for the processes, requires such marked correction that the basic model is divided into two, one for each type of process (automatic or semiautomatic). All the models have the code lines of the existing program as independent variables; the model for semiautomatic processes uses the number of modules to be extracted as a regulator of the risk of forecasting error