Studies of the software engineering process are a natural extension of scope from that of conventional software development methodologies meeting the requirement for engineering large-scale software development. A new approach for dealing with the difficulties of large-scale software development in software engineering is to establish an appropriate software engineering process system. This work researches into software engineering process system modelling and analysis. The delivered aims of this thesis are to investigate empirical software engineering process research and practices to solve current problems identified in software engineering process system modelling, to integrate current process models into a well founded and unifying framework and to lay theoretical foundations for the software engineering process as a formalised discipline.