An Approach to Integrating Systems Engineering into Senior Design
Senior design projects are essential capstone experiences to Mechanical Engineering students that allow them to integrate and apply the knowledge they attained in all of their prerequisite courses. Generally, senior students are required to engineer a system that can be purely mechanical or interdisciplinary such as a biomedical, automotive, or aerospace system. Traditionally, Mechanical Engineering curricula focus on the specifics of each component or subsystem with no regard, or at best little regard, to the overall system requirements. On the one hand, the undergraduate thermofluid sequence of courses emphasizes the fundamentals of thermodynamics, fluid mechanics and heat transfer. While, the details of thermofluid system design are usually taught at the senior or graduate level. On the other hand, design and mechanics courses focus on teaching students the aspects of analyzing certain machine elements such as shafts, pulleys, and gears. Overall systems design courses are only available in limited graduate programs nationwide. This educational approach creates a gap in students' understanding of system level requirements; thus, issues usually arise at the interfaces between subsystems in senior design projects. The current approach in senior design courses to remedy the system interface problem is Edisonian, while engineering practice is moving towards a systematic approach to design and realization. In this paper, a basic and effective approach to integrate the fundamentals of Systems Engineering into the engineering design processes is discussed. The approach consists of developing a dynamic System Level Diagram (SLD) where students transpose the system and interface requirements onto a 2 dimensional block diagram. The SLD is constructed by arranging each component and interface using flowchart methodology, where the number of components is based on the design problem while the interfaces are defined based on physical aspects such as the underlying physics, available local and distributed manufacturing facilities, and structural boundary conditions. This systems approach was adopted by graduating mechanical engineering senior design students who elected to compete in the Society of Automotive Engineers (SAE) Aero Design Competition, during which they developed a system level diagram for their system. They initially developed a layout of the RC aircraft system, then continuously updated the system level diagram throughout the design and the realization processes. The system level diagram was proven to be instrumental during the synthesis, tradeoff, analysis, fabrication, assembly, and testing phases of the project. The system diagram was also used for management, supply chain, and quality assurance aspects of the project. Overall, students reported substantial gain in their design skills and system level understanding. Introduction and background The complexity of engineered mechanical systems has been increasing with the continuous integration of electronics and software. This requires recent graduates to have multidisciplinary, system level skills. On the other hand, graduating mechanical engineering seniors lack these important skills, which created a gap between the desired skillset required by employers and those attained in the academia. This gap has been extensively discussed by the American Society of Mechanical Engineers (ASME) reports leading to the ASME 'Vision 2030' based on surveys of industry, recent graduates and academic professors This skill gap is a twofold problem with its roots at the curricula and pedagogy design level. On the one hand, the knowledge attained in the classroom is monolithic with some limited exposure to systems design, integration, and analysis, especially in the undergraduate level. Indeed, one can argue that the first exposure to 'real life' systems design is during senior design, but some can argue that this exposure is not sufficient or may be too late. Typically, mechanical engineering students with interest in mechanical systems design take three to five courses, depending on the number of units in the degree program and curriculum structure, to prepare them for jobs in design. These courses are Computer Aided Design, Introduction to Manufacturing, Statics and Dynamics, Strength of Materials, and Design of Mechanical Components (referred to as Machine Design) These courses are very important in educating students on the fundamentals of engineering, mechanics, and design, where in some cases system synthesis is emphasized. In this educational paradigm, students are expected to link the chain of knowledge together with little to no guidance. Youssef and Kabo recognized this issue and proposed a new approach to teach Machine Design, where they integrated more systems design considerations as well as soft skills such as communication They reported significant improvement in the quality of students as the students moved into capstone courses and industry; however, this course was at the junior level and their approach requires substantial investment of professors' time and effort. Based on the outcome of their study, Youssef and Kabo encouraged further integration of their approach into prerequisite courses such as statics, etc. Katz has discussed a similar approach but focused on a dynamics and vibrations course rather than machine design [3] Katz proposed an approach to bridge the gap between analytical and design thinking in general, while the approach of Youssef and Kabo emphasized the gap between systems design skills and the desired skillsets required by employers (i.e. balance between hard and soft skills) Regardless of the course in focus, these efforts are steps in the right direction and should be propagated to other cornerstone courses. It is worth noting that such integration is an ongoing effort by many professors nationwide. On the other hand, a majority of mechanical engineering programs lack courses on Systems Engineering (SE) or Systems Design at the undergraduate level. If a course is offered, it usually lacks emphasis on systems architecture, practicality beyond requirements tracking, and interface physics and mechanics. That is to say, Systems Engineering courses, the majority of which are offered only at the graduate level, are usually taught from industrial engineering or engineering management perspectives with less emphasis on the interaction and integration of multi physics subsystems and interfaces. Towhidnejad and Hillburn created a reference manual to help educators establish graduate level Systems Engineering programs with emphasis on system level competencies Alternatively, it is important to note that many other academicians have collaborated with industry and funding agencies to remedy the lack of systems engineering knowledge in graduating seniors. In separate efforts, Lee, Sheppard, and Zender et al. discussed different approaches to integrate systems thinking into capstone projects Lee reported on symbolic mathematics software tools to develop high fidelity models of complex systems in collaboration with an industry partner This approach lacked incorporation of the practical interactions between multiple subsystems while it emphasized the mathematical modeling of each subsystem. In another attempt to collaborate with industry, Zender et al. created a multiinstitutional alliance between students, faculty, industry sponsors, and workplace coaches to simulate a workplace ecosystem They integrated multiple aspects of systems engineering such as Computer Aided Design/Computer Aided Manufacturing (CAD/CAM) Product Lifecycle Management, and Project Management, to name a few. They reported sixteen lessons learned from this research, but more importantly, they presented a working structure for academia/industry collaboration. Finally, Sheppard collaborated with the U.S. Department of Defense to instill system level skills in undergraduate students by modifying elements in the curriculum Sheppard's specific focus was on developing a systems engineering framework for multidisciplinary capstone design. In that study, the focus was on programmatic and managerial aspects rather than on interdisciplinary technical aspects. The latter is the focus of this paper. Despite the reported candid efforts from academia and industry to graduate engineers with system level competence, one must wonder about the locality and narrow focus. On the locality, it is obvious that the reported efforts are still limited to a few universities and such efforts are not globalized in engineering education. Although some engineering programs try to integrate systems engineering into their curricula, the emphasis is on management and not technical aspects as discussed above. Nonetheless, professors who are teaching mechanical design and mechanics classes usually map the fundamental concepts discussed in class to a system level perspective, but of course, the main emphasis is on design and analysis of components and subsystems. In short, we remain with two simple but important questions: 1) why is Systems Engineering absent from the Mechanical Engineering curriculum? and 2) why is the focus on engineering management rather than true systems and interface design? The authors believe the answers to these questions are the same, which is encompassed in the perceived complexity of systems engineering and lack of time to integrate it into curriculum packed courses. More importantly, the limitations imposed on engineering programs in terms of number units have motivated educators to find alternative ways to deliver the same amount of knowledge without increasing the total number of units. For example, the California State University system (23 campuses, 17 of which offer engineering) has been diligently working since 2012 to reduce the requirements to only 120 semester units in an effort to reduce time to graduation. Alternatively, if a system design course is o