The Internal Family Systems Model (IFS) is an integrative approach to individual psychotherapy, developed by Richard C. Schwartz. It combines systems thinking with the view that mind is made up of relatively discrete subpersonalities (or "parts") each with its own viewpoint and qualities, feelings and needs. IFS uses familiy systems theory to understand how these collections of subpersonalities are organized.
The IFS method involves first helping the client to access Self. Then the Self gets to know a protector, discovers its positive intent, and develops a trusting relationship with it. With the protector's permission, the client accesses the exile(s) it is protecting and discovers the childhood incident or relationship that is the source of the burden(s) it is carrying. The exile is retrieved from being stuck in that past situation and helped to release its burdens. Then the protector can also let go of its protective role and assume a healthy one.
More information: https://selfleadership.org/