1. Introduction
With the development of concurrent engineering, a lot of
DFX tools have been appeared. For example, they include
design for assembly (DFA), design for manufacturing
(DFM), design for quality (DFQ) and so on. Design for
environment (DFE) or Design For Cost (DFC) is one of
the branches in DFX
[1]
Some papers have been published .
about DFC
[2] [3] [4]
And DFE have been included in a lot of .
papers
[5] [6] [7] [8]
But the relationship between DFE and .
DFC is absent.
In this paper, we provide some characters between DFE
and DFC. Then we point out how to use DFE in DFC or
use DFC in DFE. By analysis of the relationship between
DFE and DFC, we can find the method that integrated
them. Namely, LCC estimation methods can be used in
DFE; Life Cycle Assessment (LCA) can be used in DFC;
the other way is that design is evaluated using Design
Compatibility Analysis (DCA) fuzzy theory.
2. Design For Cost (DFC) and its Research Areas
Design For Cost (DFC) is a design method which
analyzed and evaluated the product’s life cycle cost
(include manufacturing cost, sale cost, use cost,
maintenance cost, recycle cost, etc.), then modified the
design to reduce the life cycle cost. Its characters can be
concluded as followed:
1) In tradition, designers attached importance to the
other parameters, but not cost. In product design process of
DFC, the LCC must be an equivalent parameter as
performance, schedule and reliability.
2) Product designers consider reducing product cost in
the whole life cycle.
3) DFC need confirming parameters of manufacturing,
usage, maintenance phases, for example, assembly cost
percent unit, usage cost percent unit. Designer should
balance performance, schedule, reliability, LCC and so on.
4) It makes sure that designers and their related
personnel communicate and feedback cost information in
time each other. So they can use some effective methods to
control product LCC.
The research areas in DFC proposed are the following:
1) Cost features are extracted using LCC analysis. Then
LCC database and LCC estimation methods base were
established.
2) In order to provide design information in cost
estimation, we must analyze design stages and models and
then extract some design features that are related with
LCC in different design models.
3) The research and development of software tools in
DFC: DFC is a design method to face designers. To
improve design efficiency and design quality, it is
important to use DFC software tools in product design
process.
4) According to market states, the balance between
design and LCC must be found. Under increasingly furious
market competition, the lowest product cost did not
enough defeat other competitors. Product must be the best
performance/price, namely provide the best functions in
the suitable price that can be accepted by users. Because
the price mostly depends on product cost and designers
decide product functions, it is essential to balance between
design and cost.
5) DFC must be integrated with the other DFX tools:
Because DFC is faced the whole life cycle, it requests that
DFC must harmonize the other DFX (DFM, DFA, etc. )
tools to work. Therefore, we should establish an evaluation
criterion to do it.
In addition, the other key technologies included how to
confirm target cost, how to select the methods of
manufacturing according to the project investment, etc.
Especially we point out that DFC is different from Design
to Cost (DTC). DFC is the conscious use of engineering
process technology to reduce LCC while DTC obtains a
design satisfying the functional requirements for a given
cost target
[9]
Further detailed distinction between the two) .
approaches can be found in the reference)
3. Design For Environment (DFE) and its Benefits
Design For Environment (DFE), also known as eco-design,
recognizes that environmental impacts must be considered
during the new product design process, along with all of
the usual design criteria. It is defined as systemic
consideration of design performance with respect to
environmental, health, and safety objectives over the full
product life cycle. There are three unique characteristics of
DFE
[10]
:
(1) The entire life cycle of a product is considered.
(2) Point of application is early in the product realization
process.
(3) Decisions are made using a set of values consistent
with industrial ecology, integrative systems thinking
or another framework.
(ISTP indexed this article)World Engineers' Convention 2004,November 2-6, 2004 Shanghai, China, Vol G, 293-296
CIMS Papers’ World 2 http://www.cimspaper.com
DFE considers the potential environmental impacts of a
product throughout its life cycle. A product's potential
environmental impacts range from the release of toxic
chemicals into the environment to consumption of
nonrenewable resources and excessive energy use. Life
stages of a product include the time from the extraction of
resources needed to make the product to its disposal.
In effect, designers design a product life cycle, not just the
product. An awareness of a product's life cycle will help
the company avoid environmental surprises and liabilities.
Ideally, the design team will seek to reduce these
environmental impacts to the lowest level possible.
DFE benefits:
DFE offers businesses opportunity to improve
environmental performance, while simultaneously
improving their profits. Companies that implement DFE
find that it:
l Reduces environmental impact of products/processes.
l Optimizes raw material consumption and energy use.
l Improves waste management/pollution prevention
systems.
l Encourages good design and drives innovation.
l Reduces costs.
l Meets user needs/wants by exceeding current
expectations for price, performance and quality.
l Increases product marketability.
DFE can also provide a means for establishing a long-term
strategic vision of a company's future products and
operations. In general, DFE is an enabling force to shape
more sustainable patterns of production and consumption.
4.The Relationship between DFE and DFC
The relationship between DFE and DFC is given in Fig 1.
Both of them belong to DFX field together. There are
some sameness and differences.
DFX
DFE
DFC
Fig1 Relationship between DFC and DFE
LCC and
Greenness
The differences:DFC is a design methodology that uses all
kind of ways to cut down production's LCC; DFE
facilitates systematic evaluation of a product and
continuous improvement goals for the entire product life
cycle. LCC is one of the design factors in DFE, it also
includes reducing environmental impact, energy supply,
raw materials and so on. Namely DFC evaluates a design
from LCC, but DFE evaluates a design from greenness.
DFC use LCC analysis methods, but DFE use life cycle
assessment (LCA) methodology.
The sameness: both of them consider the production life
cycle cost in design. And they evaluate a design from life
cycle. In DFC greenness is also considered.
4.1 The Application of LCC in DFE
The life cycle cost of a product is made of the cost to
the manufacturer, user, and society
[11]
The total cost of .
any product from its earliest concept through its retirement
will eventually be borne by the user and will have a direct
bearing on the marketability of that product.
The LCC concept was initially applied by the US
Department of Defense (DoD). Its importance in defense
was stimulated by findings that operation and support costs
for typical weapon systems accounted for as much as 75%
of the total cost
[12]
However, most of the methodologies .
developed by the DoD were not intended for use for design
but for procurement purposes.
While the life cycle cost is the aggregate of all the
costs incurred in the product’s life, it must be point out that
there are differences between the cost issue that will be of
interest to the person designing the product and the firm
developing the product in a life cycle cost analysis. While
the firm must know the total cost of the product, the
designer is only interested in the costs that he/she can
control. Some of the costs incurred in the life of the
product are not as a result of the design. These costs are
related to the way we do things. Life cycle cost can thus be
classified into management related costs and design related
costs. It is latter component that the designer is interested
in. In this paper, we mainly discussed it in DFC. One cost
category that may not be of interest to the designer is the
research and development cost. This cost is not related to
the actual design of the product but rather to the kind of
product we are developing, the resources we commit to the
process and the manner in which we use these resources to
arrive at a design solution.
TABLE I MAINLY COST ESTIMATION MTHODS [15]
Properties
Cost estimation
methods Uncertainty
Phase of
design process
Precision
Parametric Cost Method Low Early Middle
Analogy Cost Method High Late Middle
ANN Cost Method Middle Early High
ABC Method High Late High
Engineering Cost Method Low Late High
We must estimate LCC in DFE because customers can’t
purchase a product that is greenness but that they can’t
afford. There are a lot of cost estimation methods in DFC.
We can use them to estimate LCC in DFE. Table I shows
five familiar methods. In our opinion, the different
estimation methods are selected at the different design World Engineers' Convention 2004,November 2-6, 2004 Shanghai, China, Vol G, 293-296
CIMS Papers’ World 3 http://www.cimspaper.com
stages. Generally, ANN cost method can be used at the
conceptual design stage; ANN and parameter cost method
can be selected at the earlier overall (general) design stage;
Then parameter cost method can be used at the general
design stage; Finally, engineering cost method can be
selected at the detail design stage. For more detail see
Chen Ke-zhang, Feng Xin-an and Chen Xiao-chuan[13] in
English or Chen Xiao-Chuan, Liu Xiao-Bing and Feng
Xin-An [14] in Chinese.
4.2 The Application of LCA in DFC
LCA is a technique for assessing the environmental
impacts associated with a product or service
[16]
It was .
developed as an environmental policy support measure in
the past decade. LCA’s goal is to compare the
environmental impacts of different products and services
that satisfy comparable needs. To do so, all stages of the
life cycles of goods and services have to be considered, i.e.
resource extraction, production, utilization, and disposal.
So we can use LCA in DFC in order to improve
production’s greenness. For example, from life cycle
phases, the factors that can be considered as followed:
l Manufacturing: In this phase, we consider materials ,
process and product packing from greenness. We
select a design that must reduce the influence of
environment. For example, we select recycling
material
l Transportation: In transportation phase, conveyance
and handling tool can be selected from environmental
protection point. And optimization sale channel is
needed. That can decrease transportation cost and
energy supply.
l Store: Mechanical manufacturing production will not
influence the environment normally in store.
l Maintenance: In maintenance, we need notice
whether produce the trash and waste gas etc. that
pollute environment.
l Product use: In this phase, the production does not
produce waste gas and trash that pollute environment.
l Disposal: In this phase, material recycle and function
reuse are the key technologies.
In DFX, we can use Design Compatibility Analysis (DCA)
in order to evaluate a design
[17]
DCA method does not .
only include LCC but also include greenness. And it
includes manufacturing, assembly, disassembly,
serviceability and so on. How use DCA does not repeat
again in this paper. For more details please see the
reference [18].
5.Conclusions
DFE is the most effective method of improving product
environmental propert ies. From theories and facts, DFE’s
development is very quickly. In order to realize DFE’s
goals, there are not a unified technology and method. But
the substances of DFE already reach extensive common
recognitions. Now there are a lot of applications in the
world.
In this paper, the relationship between DFE and DFC is
given. Then the methods of using LCC in DFE and using
LCA in DFC are proposed. Namely, LCC estimation
methods can be used in DFE; Life Cycle Assessment
(LCA) can be used in DFC; the other way is that design is
evaluated using Design Compatibility Analysis (DCA) in
DFX.
Acknowledgement
The author gratefully acknowledges the support of
Donghua University fund and National Natural Science
Foundation of China.
References
1. Liu Jihong, DFX: design for product life cycle, CAD &
CAM, 9(1998), 34-36. ( in Chinese)
2. E. R. Dean and R. Unal, Designing for Cost, Trans. of
the American Association of cost Engineers, 35th
Annual Meeting, June 23-26, Seattle WA, 1991, pp.
D.4.1-D.4.6.
3. Chen Xiaochuan, Fang Minglun, Feng Xinan.
Application of multiple domain feature mapping in
Design For Cost(DFC), Concurrent Engineering 2002,
Cranfield University, U.K. July, 27-31, 2002, pp. 12-16.
4. Chen Xiaochuan, Yang Jianguo, Li Beizhi, Feng Xin -
an. Methodology and technology of design for cost
(DFC), The 5th World Congress on Intelligent Control
and Automation, (WCICA'04) Hangzhou, China, June
14-18, 2004, pp. 3129-3134.
5. Franke, Deborah L.; Monroe, Kenneth R., Innovative
uses of tools in the design for environment,
Proceedings of the 1995 IEEE International
Symposium on Electronics and the Environment,
Orlando, FL, USA,May, 1-3,1995, pp.503-508.
6. Harjula T., Rapoza B., Knight A.W. et al. Design for
disassembly and the environment, Annals of the CIRP,
45(1)(1996), 109-114.
7. Feldmann, Klaus; Meedt, Otto; Trautner, Stefan;
Scheller, Herbert; Hoffman, William, Green Design
Advisor': A tool for design for environment, Journal of
Electronics Manufacturing, 9(1)(2000),17-28.
8. Masui, Keijiro; Aizawa, Seiichi; Sakao, Tomohiko;
Inaba, Atsushi, Quality Function Deployment for
Environment(QFDE) to support design for environment
(DFE), 7th Design for Manufacturing Conference,
Montreal, Que., Canada, September 29-October 2,
(3)2002,. pp 415-423.
9. Dean E. B., Unal R., Elements of designing for cost.
Proceedings of AIAA 1992 Aerospace Design
Conference, February, 1992, Irvine,CA.
10.http://www.moea.state.mn.us/berc/dfe.cfm 2004.7.19.
11.L. Alting, “Life-cycle design of products: a new
opportunity for manufacturing enterprises”, Concurrent
Engineering: Automation, Tools, and Techniques. A.
Kusiak Eds. NewYork: Wiley.1993,pp.1-17.
12.Y. P. Gupta,“ Life cycle cost models and associated
uncertainties”, Electronics Systems Effectiveness andLife Cycle Costing, NATO ASI Series ,Vol. F. J. K.
Skwirzynski(ed.),1983, pp.535-549.
13.Chen Ke-Zhang, Feng Xin-An, Chen Xiao-Chuan, “A
framework of design for life -cycle cost”, Proceedings
of the International Conf. on Engineering Design and
Automation, Orlando, Florida, U.S.A. July, 2000.
14.Chen Xiao-Chuan, Liu Xiao-Bing, Feng Xin-An, “The
life cycle cost and its estimation framework in Design
For Cost(DFC) ”, China Mechanical Engineering,
vol.12, no.5, pp.510-514, 2001. ( in Chinese)
15.Chen Xiaochuan, Yang Jianguo, Li Be izhi, Feng Xin -
an. Methodology and technology of design for cost
(DFC), The 5th World Congress on Intelligent Control
and Automation, (WCICA'04)June 14-18, 2004,
Hangzhou, China
16.Helen Lewis , John Gertsakis, Design + Environment,
Greanleaf Publishing Limited, Sheffield UK, 2001.
17. Ishii K., Modeling of Concurrent Engineering Design.
Concurrent Engineering :Automation, Tools, Techniques, A.
Kusiak(ed.)(New York: Wiley),1993:19-39.
18.Chen XiaoChuan,Yang Jianguo,Li Beizhi.The
Integrated Methods and application between
DFC(Design for Cost) and the other DFX, Machine
Design and Research, 20(3) (2004),18-23. ( in Chinese)
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