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 .
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.
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'être 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