Maintainability via structure models and software metrics

The spur of innovation coming from new technologies and methodologies often leads to poorly integrated systems which evolve with no disciplined management model. We suggest a set of conceptual models for representing a system structure, differing as regards abstraction degree (essential vs. language-oriented), decomposition method (functional vs. object-oriented), and target languages. A set of software metrics is applied to system components, to single out the critical areas which require justification. Comparing measures between different versions, variants and degrees of abstraction enables to monitor the growth of entropy during software evolution