Roy conceptualizes the human system in a holistic perspective, as holism stems from the underlying philosophic assumption of the model. Holism is the aspect of unified meaningfulness of human behaviour in which the human system is greater than the sum of individual parts.
The Roy Adaptation Model sees the person as a biopsychosocial being in continuous interaction with a changing environment. The environment includes focal, contextual and residual stimuli. A focal stimulus is the confrontation with one's internal and external environment.