Subsystems and their functional requirements create balance in the behavioral system. As explained above, internal and external stimuli can disrupt the system. The primary goal of nursing as described by this model is to achieve an optimal level of patient functioning. I described the nursing process as defined by the model. I also discussed nursing tasks aimed at restoring and maintaining balance for the patient as a whole. Dorothy Johnson's Behavioral System Model of Nursing has clearly had an impact on the nursing profession today. This theory also played a major role in my professional journey.