One source of resistance to change...
Since projects by their nature introduce at least one new, "unique product, service, or result", they usually involve some elements of change. So change management is often an important component to project management. Sometimes the change is to the hosting organization and involves Organization Change Management (OCM). Sometimes it is a change to a product and marketing becomes a key component. However, the changes referred to in the PMI change control, are usually internal to the project -- for instance, changes to the deliverables and their requirements, scope, or schedule.
A book on the ADKAR method of change management
Some formalized change management methods include
- ADKAR - based on the stages of Awareness, Desire, Knowledge, Ability, Reinforcement
- Kotter's 8 Step Model - with the stages of Urgency, Coalition, Goals, Communicate, Roadblocks, Small Wins, Consolidate, Institutionalize
Change curves for different stakeholders
Related: stakeholder, organizational process assets, perform integrated change control, change management plan, organization change management plan