a framework for stepwise life cycle assessment during product design with case-based reasoning
DESCRIPTION
A Framework for Stepwise Life Cycle Assessment during Product Design with Case-Based Reasoning. Myeon-Gyu Jeong , Hyo -Won Suh , James R. Morrison Department of Industrial and Systems Engineering KAIST(Korea Advanced Institute of Science and Technology) 2010. 8 . 22. 0. Contents. - PowerPoint PPT PresentationTRANSCRIPT
A Framework for Stepwise Life Cycle Assessmentduring Product Design with Case-Based Reasoning
Myeon-Gyu Jeong, Hyo-Won Suh, James R. MorrisonDepartment of Industrial and Systems Engineering
KAIST(Korea Advanced Institute of Science and Technology)
2010. 8. 22
0. Contents
1. Research Background1. Research motivation and necessity2. Related work3. Research purpose and scope
2. Research Method1. Research framework2. Framework of CBR (Case-Based Reasoning) for LCA3. Environmental Character Evaluation Matrix (ECEM)4. Selective LCA using the result of CBR
3. Case study1. Case product and LCA result2. The LCA results and case representation3. Stage 1: ECEM and use of CBR for whole product4. Stage 2: Use of CBR for part or module5. Stage 3: Selective LCA using the result of ECEM and CBR
4. Concluding remarks
2
1. Research Background1. Research Motivation and Necessity2. Related Work3. Research Purpose and Scope
3
1.1 Motivation and Necessity
Numerous environmental Conventions (UNFCCC, Kyoto Protocol) Regulations (Reach, RoHS, EuP, WEEE, ELV) and Policies (IPP, SCEM, Environmental labaling, EPR)
Drive companies to consider eco-factors
To address environmental concerns, companies may Use an eco-design methodology for their products Develop a system to check regulation satisfaction Use environmental effect assessment methodology: LCA
● UNFCCC = United Nations Framework Convention on Climate Change● Reach, RoHS, EuP, WEEE, ELV● Eco-product related Policy - IPP, SCEM, Environmental Labeling, EPR
4
1.1 Motivation and Necessity
Streamlined LCA
is a technique that purposely adopts a [simplified approach] to life cycle assessment
Life Cycle Assessment
is an analytical methodologyto identify and assess the environmental aspects and potential impacts associated with a product throughout its life cycle
Not applicable to early product development stage Time consuming, data-intensive and sometimes difficult to communicate with non-envi-
ronmental experts Data collection and analysis challenges limit the accuracy and completeness of LCA
Limitations of LCA
5
1.2 Some Previous Efforts to Streamline LCA
Material(Acquisition)
Manufacture
Use
Disposal
Material, Energy
Air, Water, Waste
Material, Energy
Air, Water, Waste
Material, Energy
Air, Water, Waste
Material, Energy
Air, Water, Waste
Environmental Impact Assessment
BLACK BOX(ANN, Regression, etc.)
Results
Product Attribute+
Existing Full LCA resultsEnvironmental category
Life
cy-cle stage
Scoringbased on checklist
Product Attributes
Matrix Operation(Weighting, Sum.)
Results
2. Simplified LCA 3. Numerical Method1. Matrix Method
Compare results
Lear
ning
/Fi
tting
Output
(Omit indifferent process or in/output)
Ines Sousa(2000), Seo, K.K(2006)Graedel & Allenby(1995), Pommer(2001) Christiansen, K.(1997), Hur, T.(2003)
No systematic procedure to select life-stageand part/module of product
Hard to learning or fitting the black box and applicable to only specific product category& environmental stressor
Only qualitative assessment andlow accuracy of result
Suggested by
Limitations
Input
6
1.3 Research Purpose and Scope
CBR Framework for LCA• Replace complicated evaluation process with CBR• Quantitative LCA in early design stage• Using known LCA results, predict LCA results for
new product/part
FBSe expression• Function-Behavior-Structure-environmental effect• Case expression method• Support efficient use of existing LCA result cases
ECEM• Environmental Character Evaluation Matrix• Support systematic selective LCA process
Selective LCA• Selective LCA using the result of ECEM and CBR• Part selection method using CBR results
Concept design System level design Detail design
LCA with CBR/ECEM LCA with CBR Selective LCA
support
Step-wiseLCA
utilize
utilize
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2. Research Method1. Research Framework2. Framework for CBR3. Environmental Character Evaluation Ma-
trix(ECEM)4. Selective LCA using the result of ECEM
and CBR
8
2.1 Research Framework
1. Product-level evaluation using CBR
4. Select important part/module(Relative Importance)
3. Functional module evaluation using CBR
CBR
2. ECEM
Stage 1 Stage 2
Concept Design System-Level Design
Stage 3
Detail Design
Selective LCA
Quantitative LCA
Design output → Attribute Design output → Attribute
BOM(1
)BOM(2
)
Feed
back
toco
ncep
t des
ign
Feedback tosystem
-level designSupport Selective LCA
Quantitative LCA in early design stage Improved Selective LCA
with ECEM & CBR
Support eco-design with LCA result
9
2.2 Framework of CBR for LCA
Product AF B S e
Module 1F B S e
Module 2F B S e
Sub-Module 2
F B S e
Sub-Module 1
F B S e
Sub-Module 3
F B S e
Case memory
…
…
…
New Solution(LCA)
Design output → Attribute
Index
Retrieve
Select
Recall
Modify
Evaluate
Adapt
Update new case
Product Level
Module Level
Sub-ModuleLevel
Stage 1
Stage 2
Function: The purpose of the design (product) (e.g. cellular phone must communicate information to user;)
Behavior: Required functional module/parts and manufacturing process (e.g. visual information display by LCD panel)
Structure: Description of the physical characteristics of the object (e.g. geometry size, material, color)
Environmental Effect: Description of the environmental effect of a product (e.g. global warming, ozone layer depletion, acidification)
FBSe expression for case representation:
Cases are divided into three levels by product structure.Each attribute has four FBSe elements
Case memory organization and reasoning process:
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2.2 Framework of CBR for LCA
Function
Behavior
Structure
Environmental effect
Function Attribute 1(Value)
Function Attribute 2(Value)
Function Attribute n(Value)
Behavior Attribute 1(Value)
Behavior Attribute 2(Value)
Structure Attribute 1(Value)
Structure Attribute 2(Value)
Behavior Attribute n(Value)
Structure Attribute n(Value)
Case R
etrieval Area
(Used to m
atch cases)
Global warming(Value)
Acidification(Value)
Eutrophication(Value)
PhotochemicalOxidant Creation
(Value)
……
……
……
Prob
lem
spa
ce(C
BR
Inpu
t)So
lutio
n sp
ace
(CB
R O
utpu
t)C
ase Adaptation A
rea(U
sed to modify result)
……
General form of LCA results when FBSe expression is used:
By FBSe Expression, LCA result of similar module/part in different product could be retrieved and utilized
11
2.2 Framework of CBR for LCA
Product AF B S e
Module 1F B S e
Module 2F B S e
Sub-Module 2
F B S e
Sub-Module 1
F B S e
Sub-Module 3
F B S e
Case memory
…
…
…
New Solution(LCA)
Design output → Attribute
Index
Retrieve
Select
Recall
Modify
Evaluate
Adapt
Update new case
Product Level
Module Level
Sub-ModuleLevel
Stage 1
Stage 2
Weight of attribute i: wi (Nonnegative real number [1,5])Degree of similarity between cases x and y: sim(x,y) (Real number in [0,1])Values for attribute fi: fi N, fi
A (N is new design, A is case A)
𝑆𝑖𝑚𝑖𝑙𝑎𝑟𝑖𝑡𝑦 ሺ𝑁𝑒𝑤 𝐷𝑒𝑠𝑖𝑔𝑛,𝐶𝑎𝑠𝑒 𝐴ሻ= 1σ 𝑤𝑖𝑛𝑖=1 ሼ𝑤𝑖 × 𝑠𝑖𝑚ሺ𝑓𝑖𝑁,𝑓𝑖𝐴ሻሽ𝑛
𝑖=1
Similarity computation: Clos
est c
ase
is se
lect
edby
sim
ilarit
y co
mpu
tatio
n
12
2.2 Framework of CBR for LCA
Product AF B S e
Module 1F B S e
Module 2F B S e
Sub-Module 2
F B S e
Sub-Module 1
F B S e
Sub-Module 3
F B S e
Case memory
…
…
…
New Solution(LCA)
Design output → Attribute
Index
Retrieve
Select
Recall
Modify
Evaluate
Adapt
Update new case
Product Level
Module Level
Sub-ModuleLevel
Stage 1
Stage 2
IF Material category of object = Material category of
case
THEN Select case
ELSE Search other cases
(1) Checking procedure of material coincidence (2) Mass compensation
The LCA results can be affected by several factors, but highly depend on material and mass.
Therefore, it is necessary to check the coincidence of material and compensate the mass difference.
Case Adaptation:
13
2.3 Environmental Character Evaluation Matrix
Life Stage
Environmental Stressor Global warming Ozone Layer
Depletion Acidification … Average
Pre-manufacture Value (1~5) … Value (1~5) … Val. Sum
Part/Material … Part/Material … Part/Material
Product manufacture … Value (1~5) … … Val. Sum
… Part/Material … … Part/Material
Disposal… … … … Val. Sum
… … … … Part/Material
...… … … … …
… … … …… …
AverageVal. Sum Val. Sum Val. Sum …
Part/Material Part/Material Part/Material …
Input the life-stages
Important environmental stressor and related part/material information
Important life-stage and related part/material information
Purpose: to search product characterized attributes which could not be found in CBR system, and feedback the results to later design process and selective LCA
Input the value1(weak effect) ~ 5(serious effect)and related part/material
Input the environmental stressor
Searching for product attributes not found in the CBR system and for giving feedback to later design processes and selective LCA processes via E-BOM
14
2.3 Selective LCA using the result of CBR
Existing LCA method evaluate the contribution by only quantity of matter, then exclude the part which have the value below a threshold
Proposed method select important part/module based on critical value and relative importance from CBR results
Even though some part has little mass,it can have large environmental effect owing to their manufacturing process, etc.
BEGIN
IF Relative importance of part/module < Critical
value
THEN Remove the part/module from selective LCA
list
END
2. Important part selection procedure1. Relative importance
Relative importance = Total effect of moduleTotal effect of product
Use of CBR results in the selection of important parts:
15
3. Case study – Mobile Phone1. Case product and LCA results2. The LCA results and case representation3. Stage 1: ECEM and use of CBR for whole prod-
uct4. Stage 2: Use of CBR for part or module5. Stage 3: Selective LCA using the result of ECEM
and CBR
16
GW AD EU POC ARD0.00E+00
1.00E-04
2.00E-04
3.00E-04
4.00E-04
5.00E-04
6.00E-04
Nor
mal
ized
Env
ironm
enta
l Eff
ect
(pe.
yr/fu
)
3.1 Case product and LCA results
*ReferenceLCA Procedure : ISO 14040 series practical guideline, 2004. Life cycle inventory DB : KNCPC (Korea national Cleaner Production Center in KITECH
Legend:
GW : Global warming AD : Acidification
EU : Eutrophication POC : Photochemical oxidant creation
ARD : Aboic resource depletion
The LCA results for mobile phone
Back Panel
Battery PackBattery Housing
Inner Panel
Key Pad
Number Pad
LCDPCB 1 PCB 2
PCB 2Plate
Slide LWR Slide UPRSlide UPR Panel
Bolts & PlasticsFRT Panel
Mobile phone and specification
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3.2 Case representation of LCA results
Function
Behavior
Structure
Environmental effect
Phone call(Mobile phone call)
Camera(Take picture/movie)
Entertainment(Play music/movie clip)
Voice call(Speaker, Microphone)
Camera(Type:1.3M pixel CMOS)
Display module(Type: TFT LCD)
Battery(Type: Li-ion polymer)
Material(Polypropylene)
Color(Black)
Height(16.9mm)
Length(93mm)
Width(46mm)
Mass(94.9g)
Memory(Type: Flash)
Battery spec.(3.7Voltage, 800mAh) Memory capacity
(58.5 Mb)Display size
(2.0 inch)
Global warming(5.04E-04 pe•yr/fu)
Acidification(1.97E-04 pe•yr/fu)
Eutrophication(1.02E-05 pe•yr/fu)
PhotochemicalOxidant Creation
(3.69E-05 pe•yr/fu)
Azoic ResourceDepletion
(3.27E-04 pe•yr/fu)
FBSe expression of the mobile phone LCA results
18
Life stageEnvironmental Stressor
GW AD EU … ARD Average
Pre-manufacture5 5 3
…
5 4.4
Battery pack Housing/PC - PCB Housing, LCD,PCB, Battery Pack
Product Manufacture5 3 2 3 2.8- - Housing/PC - Housing/PC
Product Delivery1 1 0 2 0.8- - -
…Refurbishment,
Recycling, Disposal1 1 3 2 1.6- - Battery Pack - Battery Pack
Average3 2.4 1.6 … 2.4 Housing/PC Housing/PC,
Battery Pack … PCB,Battery Pack
3.3 Stage 1:ECEM and use of CBR for whole product
No Level Part Name Material Environmental Effect (pe.yr/fu)1 2 3 4 5 GW AD EU … ARD
1 ○ Cellular Phone - 5.04E-04 1.97E-04 1.02E-05 3.27E-042 ○ FRT CASE ASSY -
…
3 ○ FRT Pannel PC ⑤ ② 4 ○ Slide UPR PC ⑤ ②
12 ○ PCB 1 FR4 ⑤21 ○ Battery ASSY - 22 ○ Battery Housing PC ⑤ ② 24 ○ Battery Pack NMP, LiCoO2, AL… ⑤ ③ ②
ECEM (Environmental Character Evaluation Matrix):
Pre-manufacture
Productmanufacture
ProductDelivery
ProductUse
Refurbishment,Recycling,Disposal
0
2
4
GW
AD
EUPOC
ARD
0
2
4
Life stage
Environmental Stressor
Spiderweb chart helps us easily explore the important life stage,the related parts or modules, and the environmental stressor
We can estimate LCA result of whole product by using CBR, and this can be summarized in BOM with ECEM result.
Designers can modify the product based on this BOM to be more eco-friendly.
Environmental BOM(1): Based on ECEM results
19
3.4 Stage 2: Use of CBR for part or module
Value Attribute Case 1
Show image/movie Display Function
Qualcomm 233Mhz Graphic processor
BehaviorTFT LCD Display module
3.7V Li-ion battery Power source
New problem Attribute (Weight) Value
Function Display(5) Show image/movie
Behavior
Graphic processor (1) Qualcomm 600Mhz
Display module (4) TFT LCD
Display color (2) 262,000
1.0
0.8
1.0
0
Value Attribute Case 2
Show image/movie Display Function
ARM11 S3C6410 Graphic processor
BehaviorAM OLED Display module
3.7V Li-ion battery Power source
1.00.3
0.1
0
New problem Attribute (Weight) Value
Function Display (5) Show image/movie
Behavior
Graphic processor (1) Qualcomm 600Mhz
Display module (4) TFT LCD
Display color (2) 262,000
sim
sim
𝑆𝑖𝑚𝑖𝑙𝑎𝑟𝑖𝑡𝑦 ሺ𝑁𝑒𝑤,𝐶𝑎𝑠𝑒 1ሻ= 1൫5+1+4+2൯൛൫5× 1.0൯+ሺ1× 0.8ሻ+ሺ4× 1.0ሻ+ሺ2× 0ሻൟ= 0.49
𝑆𝑖𝑚𝑖𝑙𝑎𝑟𝑖𝑡𝑦 ሺ𝑁𝑒𝑤,𝐶𝑎𝑠𝑒 2ሻ= 1ሺ5+ 1+ 4+ 2ሻሼሺ5 × 1.0ሻ+ሺ1× 0.3ሻ+ሺ4 × 0.1ሻ+ (2× 0)ሽ= 0.285
Similarity computation of two different LCD modules
Case 1 is more similar to the New problem due to “Display module”The LCA results of whole product in Stage 1 and other parts or modules can be estimated with same procedure
20
3.5 Stage 3: Selective LCA using the result of ECEM and CBR
8
4
3
5
9
11
Part selection method based on CBR results is more simple and precise
Critical value = 0.02(less than 2%)
1 2 3 4 5 GW AD EU POC ARD1 ○ Cellular Phone - 5.04E-04 1.97E-04 1.02E-05 3.69E-05 3.27E-042 ○ FRT CASE ASSY -3 ○ FRT Pannel PC 9 2.86E-06 2.87E-06 1.31E-06 5.22E-06 1.43E-05 0.0864 O4 ○ Slide UPR PC 8 2.54E-06 2.55E-06 1.17E-06 4.64E-06 1.27E-05 0.0768 O5 ○ Slide UPR Pannel STEEL 6 3.87E-06 0.00E+00 0.00E+00 0.00E+00 4.96E-06 0.0142 X6 ○ Screws STEEL 1.5 9.67E-07 0.00E+00 0.00E+00 0.00E+00 3.04E-06 0.0058 X7 ○ Key PAD ASSY -8 ○ Key PAD RUBBER 0.5 1.59E-08 2.33E-08 1.94E-08 2.09E-08 3.63E-08 0.0006 X9 ○ Key PAD Ring AL 0.5 1.62E-07 1.17E-07 6.89E-08 5.15E-08 3.09E-07 0.0025 X11 ○ LCD Glass, Styrofoam…10 9.54E-06 6.49E-06 3.51E-06 9.04E-06 3.66E-05 0.1976 O
RelativeImportance
SelectPartNo Level Part Name Material Mass
(g)Environmental Effect (pe.yr/fu)
BOM(2
)
CBR result of case 1 can be adapted to new product design
21
Life stages
Considering parts
Environmental stressor
CBR
ECEM
ECEM
Selective LCA
4. Concluding Remarks
(1) CBR framework for LCA : Quantitative LCA in early design stage, Fast and effec-tive LCA by replacing complicated evaluation process with CBR
(2) FBSe expression method for CBR: Support efficient use of existing LCA cases by expressing product, module, part-level with FBSe
(3) ECEM to support CBR: Fills in gaps in eco-analysis that CBR cannot well answer
(4) Selective LCA : Part selection method using CBR results
(5) Integration of stepwise LCA procedure with environmentally extended BOM : Support gradual eco-improvement of product in each design stages
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