Aspects of the Total-System Design (TSD) approach to instructional design in medical laboratory science that was implemented at Creighton University are described. In a four-year project, TSD principles were used to produce the uniform, systematic, and complete definition of a medical technology major within a program of study leading to the B.S.M.T. degree. TSD involves the application of systems science principles to the analysis of needs and to the delivery of instruction in educational programs. Faculty members used a precise language of instruction and a top-down approach to define the knowledge, skills, and attitudes essential to entry-level gereralist practice in medical laboratory science. The TSD approach involves the extension and adaptation of the familiar behavioral objectives to produce formal goal statements with several parts: the complexity of the subject matter, the performance level at which the student will be tested, and the relative difficulty of the unit in terms of concentration and initiative required. The top-down analytical process begins with the concept of an ideal entry-level practitioner (graduating student). Each goal statement is further specified by a branching tree of substatements until the content level is reached, and specific instructional activities also facilitate the identification of prerequisites. A software management system (COMMES) is used to enhance the usefulness of these complex and extensive bodies of information. Additionally, study guides, personalized clinical instruction, instruction in human values, and information/resource sharing are part of the approach. (SW)