Reverse engineering and redesign: Courses to incrementally and systematically teach design

Journal of Engineering Education, Jul 2001 by Wood, Kristin L, Jensen, Daniel, Bezdek, Joseph, Otto, Kevin N

ABSTRACT

A variety of design-process and design-methods courses exist in engineering education. The primary objective of such courses is to teach engineering design fundamentals utilizing repeatable design techniques. By so doing, students obtain (1) tools they may employ during their education, (2) design experiences to understand the "big picture" of engineering, and (3) proven methods to attack openended problems. While these skills are worthwhile, especially as design courses are moved earlier in curricula, many students report that design methods are typically taught at a high-level and in a compartmentalized fashion. Often, the students' courses do not include opportunities to obtain incremental concrete experiences with the methods. Nor do such courses allow for suitable observation and reflection as the methods are executed. In this paper, we describe a new approach for teaching design methods that addresses these issues. This approach incorporates handson experiences through the use of "reverse-engineering" projects. As the fundamentals of design techniques are presented, students immediately apply the methods to actual, existing products. They are able to hold these products physically in their hands, dissect them, perform experiments on their components, and evolve them into new successful creations. Based on this reverse-engineering concept, we have developed and tested new courses at The University of Texas, MIT, and the United States Air Force Academy. In the body of this paper, we present the structure of these courses, an example of our teaching approach, and an evaluation of the results.

I. INTRODUCTION

In all of the material that is considered to comprise an engineering education, no subject is more enigmatic than design. Indeed, the very term "design" defies a common definition amongst engineering educators. Some represent it as a "creative, intuitive, iterative, innovative, unpredictable"8 process, a "compound of art and science,"1 that by its very nature cannot be fully described or explained. Others, eschewing such a nebulous definition, choose to think of it as a method of solving open-ended problems that is "a sub-set of the decision-making process in general."18 Despite the varied definitions, however, virtually everyone acknowledges the unique nature of "designing" and agrees that "design, above all else, defines the difference between an engineering education and a science education."16 Design, however we define it, represents the bridge between theory and reality. It is the process by which our ideas enter and influence the world around us. In short, "designing" distinguishes us as engineers.

Considering the variance in its very definition, it comes as no surprise that little agreement exists over how to teach design to undergraduate engineering students. Yet we must. One approach that has proved successful is teaching students a structured, problemsolving method that they may use to tackle open-ended design problems. Of these methodologies, four of the most popular are those of Otto and Wood,75 Pahl and Beitz,29 Ullman,42 and Ulrich/Eppinger.32 Indeed, many of the papers reviewed here base their teaching methods upon one of these three. Yet even if the overall methodology is the same, the specifics of the various ways engineering design is taught vary substantially. Given this diversity, the questions arise: what underlying deficiencies exist in current design education, and what new approaches can we recommend to address these deficiencies and fulfill our roles as engineering design educators?

In this paper, we answer these questions based upon a new approach for teaching engineering design methods,43 that of product evolution or redesign. As with any design problem, redesign includes the process steps of understanding customer needs, specification planning and development, benchmarking, concept generation, product embodiment, design for manufacturing, prototype construction and testing, and production. Yet, redesign also focuses on an additional and critical step, referred to here as reverse engineering.43,53 Reverse engineering initiates the redesign process wherein a product is predicted, observed, disassembled, analyzed, tested, "experienced," and documented in terms of its functionality, form, physical principles, manufacturability, and assemblability. The intent of this process is to filly understand and represent the current instantiation of a product. It is here, through this process, that we can impact design education. By providing reverse engineering projects and new techniques to support the projects, we can provide concrete experiences for students as they learn design methods. No longer will students face a blank drawing board as they encounter their first design experience, but they will have day they can mold, test, and refine. No longer will students be asked to experience only a single capstone design with no chance at observation and reflection, but rather can incrementally experience a design process and observe and reflect on each step (with a previous existing product) to compare their results.