Engineering Communication Skills and Design for Manufacturing - A Freshman Engineering Course


Corrado Poli

Department of Mechanical Engineering

University of Massachusetts Amherst

Amherst, MA 01003



Abstract

This paper describes a new one semester freshman course which uses a semester long design for manufacturing project as a mechanism for teaching critical thinking, communication skills and team work. The development of written, oral and graphical communications skills are included in the course


Introduction

The 'Towards World Class Manufacturing 1993' conference held in Phoenix and hosted by the International Federation of Information Processing TC5 in cooperation with the Society of Manufacturing Engineers, was attended by several vice-presidents of engineering, representing international corporations from both the US and abroad. As each one spoke, they stated, in more or less the same words, that 'old habits are hard to break.' As a result, they said, the sequential mode of operation depicted in Figure 1 is still the prevalent mode of operation found in industry today. It begins with the conception of an idea for a new product which, if approved, is first designed, engineered, and analyzed for function and performance. The design is then detailed and production drawings are then handed over to manufacturing.

These same vice-presidents stated that there are two main problems with this approach:

a) Decisions made during the early conceptual stages of design have a great effect on subsequent stages. In fact, quite often more than seventy percent of the manufacturing cost of a product is determined at this conceptual stage. Yet, manufacturing is not involved during these early stages.

b) No single person or group is in charge. Each group blames the other for problems, difficulties and delays and the process goes out of control.

They went on to propose two solutions to this problem. The first solution was to form teams which involve everyone from the beginning to the end of the entire life cycle (Figure 2). With the team approach the team is in charge of the product from cradle to grave .

Figure 1. Present Situation in Industry



Figure 2. The Team Approach

Industry, they said, was good at using the team approach and at carrying out product and process design simultaneously.

The second solution was to educate designers about manufacturing. Industry, they said, was not good at this. They went on to say that industry is not good at capturing design history, and is not good at developing the kind of structured methodologies needed to educate engineers. However, they stated, universities are good at this.

At the University of Massachusetts Amherst (UMass) we are in agreement with most of the statements that were made at this conference and we are in particular agreement with the statement concerning the ability of universities to develop structured methodologies for use by designers. In fact, for the past 15-20 years, faculty members at UMass have been involved in developing such structured methodologies [1-11]. These faculty members have been developing design systems, for use by designers who are not necessarily experts in manufacturing, to support evaluation for manufacturability. The systems they have developed can be used at both the early stage in the design process where the general configuration is established, and at the detailed or parametric stage of the design process. The purpose of this paper is to describe a new freshman course which makes use of some of these methodologies, albeit at a less sophisticated level than the original methodologies.

The Past and The Present

Over the years, comments by members of the College of Engineering's Dean's Advisory Council, indicated that it is impossible for engineering faculty to over-emphasize the importance of effective communications, team work and design for manufacturing. During this same time period, exit interviews with members of our freshman class indicated that they were bored and unmotivated by our current freshman program. This program, which is similar to those found in almost every college of engineering in this country, is a course which is comprised of a series of isolated abstract topics dealing with programming, computer-aided drawing, spreadsheets, etc., and contains little if any engineering content. The course is taught by one faculty member, dedicated to the freshman program, who lectures to sections of 100-200 students, and by TAs in laboratory sections of about 24 students. At the end of their freshman year the majority of UMass students believe they have no better knowledge of what engineering is about than what they did at the start of their freshman year.

Because of this, we are in the process of developing a new two-course sequence. In this new sequence sections will be comprised of 24 or fewer students, instead of the present 100 or more students. Since no faculty member will teach more than one section, then 10-15 faculty members per semester will be involved teaching freshman, instead of 1. Finally, the laboratory portion of the courses will, as much as possible, be supported by undergraduate teaching assistants (UTA) who will act as mentors. The first semester course will emphasize communication skills, teamwork and design for manufacturing. The second semester course, which is still under development, will consist of one or more of the following types of modules, namely, computer tools modules, departmental modules which are designed to reinforce communication skills and introduce additional manufacturing concerns, and semester long departmental courses designed to complement the first semester course. This paper is devoted to a description of the first semester course.

The Future

The new first semester freshman course, which was first taught to a pilot section of 12 students during the Spring 1994 semester, emphasizes communication skills, team work, and design for manufacturing (DFM). The communication skills emphasized are written, oral and graphical. Teamwork is provided by the use of a semester long DFM project in which students, working in teams of two or three, are required to redesign a consumer product of their choice. The manufacturing concepts introduced are primarily qualitative in nature while the quantitative design for manufacturing methodologies used are less sophisticated versions of those covered in our upper level undergraduate and graduate level courses. Since the vast majority of special purpose parts, that is those parts whose form features are designed in by the designer and which are not selected from catalogs, are either injection molded, die cast or stamped, the DFM methodologies introduced are primarily restricted to those three processes. In addition, a greatly simplified version of Boothroyd's original design for manual assembly methodology is covered [2, 12, 13].

This three credit hour course consists of two 50 minute lectures per week and one 3 hour laboratory. The lectures are used to cover basic concepts and theory and to discuss the assigned homework problems. The labs are used to learn AutoCAD, view tapes of various manufacturing processes, and for work on the project. The lectures are handled by the faculty member, the labs are handled primarily by UTAs.

During the first week of the course, and in each section of the course, the students are divided into teams of 2 or 3 students. While students are given a chance to select their own partners, those unable to do so are randomly assigned to teams. After formation of the teams each team is either assigned, or required to select on their own, an assembly (consumer product) such as a telephone, hair dryer, audio tape, video tape, beard trimmer, etc., or subassembly, such as a carburetor, alternator, etc. The assembly or subassembly chosen must have a potential annual production volume of at least 50,000 assemblies. The reason for insisting on such a 'high' production volume is so that students will select products which are composed of piece parts components produced using today's most common mass production techniques, namely, injection molding, stamping, and die casting.

It is suggested that the assembly or subassembly chosen contain about 15-20 parts. If there are fewer than about 15 parts, then the variety of parts is insufficient to make the project interesting. If there are more than about 20 parts, the project becomes too burdensome for the time available in this freshman course. Since most of the students in the class have never been exposed to mechanical drawing, students are told that in selecting a product they should be aware of the fact that straight lines are easier to draw than curved lines.

Following selection of their product, each team is required to first produce an assembly drawing of their product. Thus, the first four weeks of the course (8 - 50 minute lectures) are devoted to drawing. These lectures are devoted to discussing orthographic projections, pictorial views, sectional views and assembly drawings. It is not the goal of this drawing 'module' to teach students how to produce detailed working drawings, but rather how to produce assembly drawings that can be used to support their assembly analysis. The first four 3-hour laboratories are devoted to learning AutoCAD. AutoCAD is essentially self-taught using a tutorial book. Undergraduate teaching assistants are available to provide assistance. There is little faculty involvement with the laboratory section of the course. Each section of the course is assigned to the same laboratory section so that each team has at least one 3-hour time period per week when the team can meet and discuss their project.

Since one of the main objectives of the project is to analyze and redesign each product for ease of manual assembly, the next portion of the course, about 3 lectures, is devoted to a study of manual assembly. Using a structured methodology presented in class, each team estimates the time required to assemble the product manually. Each team also redesigns their product in order to reduce assembly time, hence assembly costs, and estimates the total savings that can be achieved with their redesign.

About mid-way through the semester students are required to provide a written progress report. In addition, each team makes an oral presentation describing their progress to date. Thus, the next portion of the course is devoted to developing written and oral communication skills. The written communication portion of the course stresses business technical report writing, as opposed to research report writing, and emphasizes recommendations, results and conclusions. Exercises dealing with titles, abstracts, introductions and results are assigned and then reviewed in class. Guidelines for the preparation and delivery of oral reports are also covered. Students are also required to prepare an oral presentation to accompany a previously assigned written exercise. All of this occurs prior to the submission and oral presentation of their progress report.

The next portion of the course, to the extent that time permits, deals with design for injection molding, die casting and stamping. Again, using the structured methodologies discussed in class, teams estimate the manufacturability of both the original designs of the piece-part components and their proposed redesigns. Detailed part drawings (isometric drawings, orthographic projections, sectional views, etc.) are required for each injection molded, die cast or stamped component.

At the end of the semester, each team is required to submit a final business technical report and to make a final oral presentation. Figures 3 and 4 show assembly drawings, including the manual assembly characteristics of each part, produced by two of the teams from the pilot section of the course. None of the team members had ever had a drawing course in high school and none had ever used a computer aided drawing program prior to this course. It should also be pointed out that the redesign of the Kao floppy disk (Fig. 3) proposed by the freshman design team was of sufficient quality to attract the attention of Kao.


Figure 3. A Drawing by Matt Roy and Jean Maranville for a Freshman DFM Project


Figure 4. A Drawing by Kevin Horgan and Nithin Shenoy for a Freshman DFM Project

Course Materials

This new course is centered around two (of the twenty four) chapters in J. R. Dixon and C. Poli's new book entitled, "Engineering Design and Design for Manufacturing - A Structured Approach." The two chapters used are Chapter 3, Introduction to Manufacturing for Designers, and Chapter 22, Communications. Because the book was never written with this course in mind, the various sections of the chapters are not covered in the order presented in the book. In fact the course begins with the very last section of Chapter 22, Graphical Communications, then jumps to that section of Chapter 3 dealing with assembly, and then returns to Chapter 22 and covers the sections dealing with written and oral communication. The course then returns to Chapter 3 and finishes off with polymer processing, casting and stamping. Since Fieldstone Publishing will, for a small charge, permit university book stores to reproduce Chapters 3 and 22, it is not necessary for freshman to purchase the entire book

Certain portions of James Earle's book, "Engineering Design Graphics, 7th edition" are used to supplement the graphical communications material which appears in Dixon and Poli. In particular those chapters dealing with multiview sketching and drawing (Chapters. 14 and 15), auxiliary views (Chapter 16), sectional views (Chapter 17, and assembly drawings (section 24.12) are used. This book provides self-instruction examples for the student and links to AutoCAD release 11. Once again permission is sought from Addison Wesley, publishers of the book, to reproduce these few chapters in order to keep overall student costs down.

The third book used in this course is the Prentice Hall book, "Discovering AutoCAD," by M. Dix and P. Riley. This book is tutorial in nature and has proved adequate for self-instruction of AutoCAD.

Finally, to assist students in better visualizing and understanding those portions of the course dealing with the tooling aspects of injection molding, die casting and stamping a series of intelligent tutors is currently under development by Dr. Beverly Woolf of the UMass Computer Science Department and the author. The objective of these tutors is to provide interactive, multimedia environments in order to improve student understanding of the complex relationship between part geometry and tool complexity. In specific students, who have never seen an actual tool, are able to create a limited number of parts and then, via animation, see the process in operation as the part is created using alternative forms of tooling.

Course Evaluation

To date the course described here has been given twice. Once to a pilot section of 12 honors students in the Spring of 1994, the other time to about 100 freshman in the Fall 1994 semester. In the case of the pilot section, the course was self-selected by the students. In the case of the Fall offering, it was self-selected by about half the students. The remaining 50 percent were randomly selected. While the pilot section was taught by a mechanical engineering faculty member, the Fall 94 sections were taught by three faculty members from mechanical engineering, one from industrial engineering, and one from the electrical and computer engineering department. These faculty members met on a weekly basis to share ideas, learning experiences, and to discuss the following week's lesson plan.

When members of the pilot section of the course were questioned by members of the Dean's Advisory Council, they almost all agreed that the course was primarily about communication skills and only secondarily about manufacturing.

When members of this year's freshman class were asked, at the end of the first semester, whether or not they now had a better understanding of what engineering is, approximately 92% of those in the new course said yes, while only 55% of those in the old freshman course said yes. However, 25% of those in the new course felt that what they really obtained from the course was a better understanding of what mechanical engineering is about and still didn't have a sufficiently good idea of what other engineering fields are about. While there may be some truth to this, the purpose of the second semester course, with its departmental modules, is to give students a better idea of what does go on in other departments outside of mechanical engineering. Many of the students in the old course (about 25%) felt the course was about software and computers, and was not about engineering.

In general students were pleased with the new course and were pleasantly surprised that as first semester freshman they were involved in a hands on DFM project. Interestingly, the results of the student course evaluations did not seem to be dependent on the home department of the faculty member teaching the course.

While faculty members in the College of Engineering felt that this course would tend to steer students to selecting mechanical engineering as their major of choice, only 2 members of the pilot section in fact decided to major in mechanical engineering. During this past year when the course was expanded to include about 100 of the 240 incoming freshman, the percentage of students from both the new program as well as the old program who selected mechanical engineering as their major was approximately 24%. In reality the distribution of these students among the various departments in the College of Engineering was about the same as that for the freshman population as a whole.

One of the hoped for outcomes of this new course was a reduction in the number of students dropping engineering as their major. While it is perhaps a bit too soon to decide whether or not this will occur, for the 1994-1995 academic year the percentage of students dropping engineering was the same for both those who took the new program as well as for those enrolled in the old program.

Transportability

A question that naturally arises concerning the course is its transportability. While this particular course has been centered around the theme of design for manufacturing, particularly as taught in mechanical and/or industrial engineering departments, it need not be. The main objective of the course is to use a semester long engineering project in order to introduce students to the field of engineering and to provide the stimulus for learning team work, creative thinking and communication skills.

While the course material described here is the course material used for the UMass version of the course, any combination of books which contains the course material to be taught will work. The two most important ingredients required to make the course successful are small sections, to permit a more intimate relationship between the class and the faculty member, and the faculty themselves. Because the course is faculty intensive, many faculty members, including those outside of mechanical engineering must become involved. At UMass, it is the intention of some of the departments to rotate the assignments to the freshman course among all the faculty, particularly among all the design, manufacturing and materials oriented faculty. However, many of the UMass faculty outside of mechanical engineering, feel uncomfortable with the prospects of having to teach such topics as drawing, manufacturing and design for manufacturing. For them to feel comfortable with the course they will, of course, need to add their own particular wrinkle to the course. Unfortunately, the alternative versions proposed to date lack the hands-on semester long projects which brings together the raison d'Ítre for teaching those topics required to carryout the project. And in this sense these alternative courses appear to resemble more the old freshman computer skills course that is being phased out. While it is inevitable that the course will change as more and more faculty members become involved, it will probably require strong leadership on the part of the Dean to see that the course does not gradually return to the less faculty intensive courses of the past.

Acknowledgments

The author would like to express his appreciation to the Technology Reinvestment Project, the National Science Foundation, and the Engineering Academy of Southern New England for the financial support provided in support of this program.

References

(1) G. Boothroyd, C. Poli, and L. E. Murch, "Feeding and Orienting Techniques for Small Parts," University of Massachusetts Amherst, Mechanical Engineering Department, Amherst, MA, 1978

(2) G. Boothroyd, "Design for Assembly Handbook, "Mechanical Engineering Department, University of Massachusetts Amherst, Amherst, MA, 1980

(3) W. A. Knight and C. Poli, "Design for Forging Handbook, (with W. A. Knight), Mechanical Engineering Department, University of Massachusetts/Amherst, Amherst, MA, 1984

(4) C. Poli and S. Rajagopalan, "Design for Injection Molding and Die Casting - A Knowledge Based Approach," Proceeding of ASME International Computers in Engineering Conference, Santa Clara, CA, August 1991, pp. 53-59

(5) C. Poli, P. Dastidar and P. Mahajan "Design for Stamping - Analysis of Part Attributes that Impact Die Construction Costs for Metal Stampings," Proceedings of the ASME Design Automation Conference, Miami, September 1991

(6) C. Poli and S. Shanmugasundaram, "Design for Die Casting - An Integrated Approach," Proceedings of the ASME Design Theory and Methodology Conference, Miami, September 1991

(7) C. Poli, P. Dastidar and R. Graves, "Design Knowledge Acquisition for DFM Methodologies," Research in Engineering Design, 1992

(8) C. Poli, S. M. Kuo and R. Graves, "Design for Injection Molding: a Group-technology-based Approach," (with), Journal of Engineering Design, Vol. 3, No., 1992

(9) C. Poli, P. Dastidar, and P. Mahajan "Design for Stamping, Part II - Quantifications of Part Attributes and Tooling Cost," Proceedings of the ASME Design Theory and Methodology Conference, Phoenix, September 1992

(10) C. Poli, P. Dastidar, P. Mahajan, and R. J. Graves, "Design for Stamping - Analysis of Part Attributes that Impact Die Construction Costs for Metal Stampings,", Journal of Mechanical Design, Vol. 4, pp. 131-145, Vol. 115, pp. 735-743, 1993

(11) C. Poli, P. Dastidar, P. Mahajan, and R. J. Graves, "Design for Stamping: A Group Technology-based Approach," Concurrent Engineering: Research and Applications, Vol. 1, pp. 203-212, 1993

(12) G. Boothroyd, and P. Dewhurst, "Product Design for Assembly," BoothroydDewhurst Inc. Wakefield, RI, 1989

(13) G. Boothroyd "Assembly Automation and Product Design," Marcell Dekker, New York, 1992