Fennell proposes a model for management of chronic illnesses such as chronic fatigue syndrome and multiple sclerosis by using a systems approach that comprehensively integrates the biological, psychological, sociocultural, and spiritual dimensions to determine the common elements underlying their manifestation and management. This model considers that a person's body, mind, family, friends, clinicians, colleagues, and community are essential contributors to the total system. Changes that occur in one part of the system affect all other parts. The four phases experienced by people with chronic illness include crisis, stabilization, resolution, and integration. Although these phases are sequential, the model recognizes that individuals may move backward and forward and sometimes exhibit signs of being in more than one phase simultaneously. The treatment approach assumes that patients who successfully navigate the four phases will achieve integration rather then cure. Fennell writes, "most of the assumptions of this model are neither novel nor original."