22
2.7.1 Definition of Engineering Process
Yousef Haik 2003 states that the Clive L. Dym was defines the design as the systematic, intelligent generation and evaluation of specification for artifacts whose
form and function achieve stated objectives and satisfy specified constraints. A formal definition of engineering design is found in the curriculum guidelines of the
Accreditation Board of Engineering and Technology ABET. It states the engineering design is the process of devising a system, component or process to meet
desired needs.
The engineering design component of a curriculum must include most of the following features such as development of student creativity, use of open-ended
problems, development and use of modern design theory and methodology, formulation of design problem statement and specifications, product processes,
concurrent engineering and detailed system description. Furthermore, it is essential to include a variety of realistic constraints such as economic factors, safety,
reliability, aesthetics, ethics and social impacts.
2.7.2 Design Process
Design is create a new product that turns into profits and benefits society in the same way. The ability to design requires both science and art. The science can be learned
through the systematic process, experiences and problem solving technique. The art is gained by practices and total dedication to becoming proficient. The design system
can be done in one of two ways such as evolutionary change and innovation.
a
Evolutionary change: A product is allowed to evolve over a period of
time with only slight improvement. This is done when there is no competition. The creative capabilities of the designer are limited.
b
Innovation: Rapid scientific growth technological discoveries as well as
competition among companies for their slice of the market have placed a great deal of emphasis on new products which draw heavily on innovation
23 the creative skill and analytical ability of the design engineer play n
important role.
Proficient designers control the evolution and innovation so they occur simultaneously. Although the emphasis is on innovation, designers must test their
ideas against prior design. Engineers can design for the future but must be based on the past.
Figure 2.5, Figure 2.6 and Figure 2.7 show the charts that described the design process which are offered by the 3 authors whose are Clive L.Dym, Johnson and the
Pahl and Beitz.
Clive L. Dym is the Fletcher Jones Professor of Engineering Design and Director of the Center for Design Education at Harvey Mudd College. His interests include the
design theory, knowledge-based expert system for engineering design, and structural and applied mechanics. He has previously served at the University of
Massachusetts at Amherst 1977-1991, Bolt Beranek and Newman 1974-1977, Carnegie Mellon University 1970-1974, Institute for Defense Analyses 1969-
1970 and the State University of New York at Buffalo 1966-1969. He completed his B.S.C.E at Cooper Union and M.S at Broolklyn Polytechnic Institute on 1964 and
gets the Ph.D at Stanford University on 1967.
He has published more than 100 archival journal articles, proceedings papers and technical report. He also has served on the editorial boards of several journals and
has edited six volumes and written ten of books and the last including of Engineering Design: A Synthesis of views
, Cambridge University Press on 1994 and the Engineering Design: A Project-Based Introduction
co-authored by P.Little, John Wiley Sons on 1999 and 2003. He also a member of the American Society of
Engineering Education and has been elected a Fellow of the Acoustical Society of Civil Engineers. Apart of that, he also won
ASCE’s Walter L. Huber Research Prize on 1980,
ASSE’s Western Electric Fund Award on 1983 and the Fred Merryfield Design Award
on 2002 and was the first runner-up for the 2001 Boeing Outstanding Engineering Educator Award.
24 Jerome B. Johnson is one of the author’s Engineering Design book. He is explained
about the design process map which includes the market survey, information search form the past work, mechanical design synthesis and the profit that get from the
Production-distribution-consumption-recovery cycle.
Prof. G. Pahl and Prof. Wolfgang Beitz are one of the authors of the Engineering Design. The difference in these charts is in the sequence names. Careful examination
of the charts leads to identification of the same stages and the some stages combined in the one process.
25
Figure 2.7: Design process map From Johnson, 1978.
Problem recognition and definition
Market Survey
Information search
Past work
Synthesis of configurations
Systematic technique
Creative ingenuity
Feasibility calculations
Selection of optimum configuration
Selection of material and dimensions
Optimization technique
Cut and Try
Manufacturing Specifications and model constructions
Production-distribution-consumption- recovery cycle
Design analysis and evaluation
Theoretical
Experimental Design reject
Profit Idea
Reject 3
8 7
6 5
4 2
1
Mechanical design synthesis
26
Figure 2.8: Design process map From Dym, 1994.
Specified function
Actual function Technical requirements and
specified costs Task
0.1 Specifications and analysis of
product environment
1.1 Determination of overall
function structure 1.2
Determination of special function structure
Comparison of specified and actual functions
2.1 Form design and material
selection 2.2
Design for production
Actual function Actual Costs
Comparison
Actual Specified functions Actual Specified costs
Production drawings
Product
0. Task Formulation phase
3. Result 2. Form Design
Phase 1. Functional
phase
27
Figure 2.9: Design Process map From Pahl and Beitz, 1996.
Task Clarify the task
Elaborate the specifications
Identify essential problems Establish function structures
Search for solution principles Combine and firm up into concepts variants
Evaluate against technical and economic criteria
Finalize details Complete detail drawings and production documents
Check all documents Develop preliminary layouts and form designs
Select best preliminary layouts Refine and evaluate against technical and economic criteria
Upgr ade
a nd im
pr ove
Optimize and complete form designs Check for errors and cost effectiveness
Prepare the preliminary part list and production documents Specification
Concept
Concept Definitive layouts
Preliminary layouts
Solution C
lar ifica
ti o
n of the task
C onc
eptual de
sign
Embodi ment de
sign
De tail De
sign Optim
iza ti
on of the pr
inc ipl
es
28
2.7.3 A Generic Development Process
Kategori