An approach and basic concepts for the study of the system dynamics of long-term software evolution processes is presented. The approach provides a generic context and framework that supports at least three crucial process areas requiring management decision, resource allocation, release planning, and process performance monitoring. The report exemplifies the approach with an executable model. The latter reflects the global software process at a high level of abstraction and includes phenomenological observations derived from the laws of software evolution and the behaviours thereby implied. It incorporates concepts such as progressive (e.g., functional enhancement) and anti-regressive (e.g., complexity control) activities and enables the study of policies of human resource allocation to classes of activities. The example shows how the model permits assessment of the impact of alternative policies on various evolutionary attributes. It is part of and exemplifies the methods for software process modelling being developed and applied in the FEAST projects
