Reference #273: The First 90 Days
To understand the influence landscape in your organisation, consider mapping influence networks. These show who influences whom on issues that concern you.
Influence networks are channels for communication and persuasion that operate in parallel with the formal structure, as a sort of shadow organisation.
Formal authority is not the only source of power and influence in an organisation. Expertise, the respect and loyalty of one's peers, control of information, connections to others, and access to resources such as budgets and rewards also create influence.
Watkins. The First 90 Days, 2013. (203-206)