C10.7.5.3.1 Organisational Structure
Organisations may have a formal or an informal structure.
Formal organisational structures are the where roles and responsibilities are defined, as are communication channels.
Informal organisational structures are where the personal relationships and communication channels are used more frequently. For example, where employees are related to one another, live near each other or play golf together outside of work. This will all influence communication, and you cannot create an organisational chart that accounts for all of these relationships.