A very useful and powerful basis for the management of IT Governance Processes is the so called COBIT Framework (COBIT = Control Objectives for Information and related Technology).
COBIT is the leading framework for governance and management of Enterprise IT (https://lnkd.in/eVhrkXu). It can easily be combined with ITIL and other IT frameworks which are focussed on operation and maintenance of IT. COBIT comprises 37 standard process descriptions clustered in 5 domains including e.g. control-objectives or key performance indicators.
Complementary to COBIT the following picture shows a proven format for a user friendly and comprehensible process description (also applicable for business processes), which I have successfully used in various reorganization projects in the past.