S ystems analysis attempts to describe and improve a system by studying its component parts, the interrelationship between those parts, and the energy used within the system to produce a final product (Hazzard, 1971). This method works well in manufacturing because factories produce objectively observable products, and each step of the process, from raw materials to finished product, can be measured. It is more difficult to apply systems theory to the health care field because the "product" is more subjective and less measurable. Health care systems are complex structures that use advanced technology, depend on trained and specialized professionals, and provide service (Conrad, 1988). Another issue in applying systems theory to health care is lack of information about the system and its numerous elements (Kast, 1981). For these reasons, systems theory has not been widely applied in the health care field.