Author(s): Meir M Lehman
By clppsitying programs according to their relationship to the environment m which they ne executed, the paper identities the sources of evolutionary pressure on computer rpplicitim and pro- grams and shows why this results in a process of never ending mainte- nance activity. The resultant Life cyde processes ne then briefly dis- cussed. The paper then introduces laws of Rognm Evdution that have been formulated fdlowing quantitative studies of the evolution of a number of different systems. Finally an example is pravided of the application of Evdution Dynamics models to program release plnnning.