Transcript 슬라이드 1

Design for Manufacture &
DFX
Park, Mok-Min
2004, 05, 10
MAI Lab. Seminar
Design for manufacture and design for ‘X’:
concepts, applications, and perspectives
Computers & Industrial Engineering 41 (2001) 241-260
Tsai-C. Kuo, Samuel H. Huang, Hong-C. Zhang
Dept. of IE and Mgt, Minghsin Institute of Technology, Hsinchu, Taiwan, ROC
Dept. of ME, IE, and NE, Univ. of Cincinnati, USA
Dept. of IE, Texas Tech Univ., USA
Historical background

Engineering design


원하는 요구를 만족시키기 위하여 시스템, 컴포넌트나 프로
세스를 개발하는 일련의 과정
Two approaches: after a design is completed


Value Engineering (VE): 제품의 기능과 가격을 고려
Producibility Engineering (PE): 가용한 기술과 툴을 이용하
여 적절한 비용으로 생산

Limits of VE & PE



제품의 제조 가능성을 초과하는 최적해
VE는 과학적인 접근보다는 회사의 정책에 연관
디자인이 결정되면 대부분의 비용이 이미 결정
1/20
Design for Assembly (DFA)

Boothroyd & Dewhurst(1987)’s DFA method





Two factors



기본적인 기준을 이용하여 각 부품이 왜 필요하고 다른 부품과 합
쳐져야 하는지에 대해서 자문
특별히 구축한 DB의 실시간 표준을 이용하여 조립 시간을 개산
Design efficiency는 실제 조립 시간과의 비교를 통하여 구함
제조나 품질에서 문제를 일으킬 수 있는 assembly difficulty를 파
악
The total number of parts
The ease of handling, insertion, and fastening of the part
Applications



Hitachi: Assembly Evaluation Method (AEM)
Sony: Design for Assembly Cost effectiveness (DAC)
GE: manufacturing producibility handbook, workshops
DFA DFM DFD DFR DFE DFLC DFQ DFMt
2/20
Design for Manufacture (DFM)

Processes for the manufacture of a particular part





표준 컴포넌트 사용
범용 부품 설계
조립 방위 최소화
Stoll(1988) cited a checklists of DFM guidelines
Many DFM studies have been completed





원자재 선택
프로세스 선택
모듈 디자인 개발
Machining parts (Booth & Radovanovic, 1989)
injection molding (Dewhurst, 1987)
sheet metal stamping (Zenger & Dewhurst, 1988)
die cast parts (Dewhurst & Blum, 1989)
DFM applications can be carried out with great efficiency
via a CAD/CAM system
DFA DFM DFD DFR DFE DFLC DFQ DFMt
3/20
Design for disassembly (DFD)

Two basic methods of disassembly (Leonard, 1991)


Some obstacles (Seliger, Zussman & Kriwet, 1993)




reverse assembly, brute force
Difficult to gain all the information
Parts might have been modified during repair
Wear can make joined elements
Determination of disassembly sequence



Dewhurst(1991)
Gu and Yan(1995): a graph-based heuristic approach
Etc.
DFA DFM DFD DFR DFE DFLC DFQ DFMt
4/20
Design for recyclability (DFR)


Environmental conscious increases
The aim of recycling




Maximize the recycling resources
Minimize the mass and pollution potential of
remaining products
DFM of plastics that can be easily recycled
Dismantling techniques and recycling costs
DFA DFM DFD DFR DFE DFLC DFQ DFMt
5/20
Design for environment (DFE)

Three main goals of DFE (Hovath, et al. , 1995)




Minimize the use of non-renewable resources
Effectively manage renewable resources
Minimize toxic release to the environment
HP provides DFE tools (Korpalski, 1996)



DFE guidelines
Product assessments
Product stewardship metrics
DFA DFM DFD DFR DFE DFLC DFQ DFMt
6/20
Design for life-cycle (DELC)

Life-cycle
phase
Need
Design
Product life-cycle cost (Jovane, 1993)
Company costs
User costs
Society cost
market recognition
development
Production
materials, energy, facilities,
wages, and salaries
Distribution
transportation, storage, waste
transportation,
storage
Waste, pollution, packing, health
damages
warranty service
energy, materials,
maintenance
Waste, pollution, health damages
Disposal
disposal dues
Waste, pollution, disposal, health
damages
Recycling
recycling dues
Waste, pollution, health damages
Use
Waste, pollution, health damages
DFA DFM DFD DFR DFE DFLC DFQ DFMt
7/20
Design for quality (DFQ)

The objectives of DFQ (Crow, 1983)




Meet customer requirements
Robust product
Continuously improve product reliability,
performance, and technology
Methods of DFQ



Taguchi method(1986)
Quality Function Deployment (QFD)
Benchmarking
DFA DFM DFD DFR DFE DFLC DFQ DFMt
8/20
Design for maintainability (DFMt)

Maintainability is (Kapur & Lamberson, 1977)


Objective of DFMt


The probability that a failed system can be repaired in a
specific interval of downtime
The product can maintained throughout its useful life-cycle
at reasonable expense without any difficulty
Maintainability design guidelines





접근성
고장의 확인
교체 부품의
교체 부품의
교체 부품의
및 격리 능력
비중 한계
운반 가능성을 고려한 크기 한계
자동(원격) 교체 가능성
DFA DFM DFD DFR DFE DFLC DFQ DFMt
9/20
Summary





여러 측면에서의 설계 목적과 제약 사항들을 사전에
고려하여 더 나은 제품을 설계
DFMA를 통해서 낮은 비용으로 용이한 제품 생산
DFD, DFR, DFLC를 통해서 제품의 수명 주기 후에
처리를 용이
DFE를 통해서 환경적인 안전과 건강과 관련된 문제
들을 해결하고 간접적인 비용을 절감
DFQ, DFMt를 통해서 검사, 재작업, 진단에 소요되
는 비용을 절감
10/20
Future trends

Integration issues in DFX




Human factors engineering in DFX


Systematic identification of user’s life-cycle requirements
Methods to represent, store, and retrieve design
alternatives
Comprehensive measure of goodness of a design
Workplace design, human-equipment interface, training
program
Intelligent DFX systems


필요한 경험을 쌓는 데 많은 시간이 소요
Knowledge-based system을 이용하여 design feature 간의 관
계를 이해하는 데 도움을 줄 수 있다.
11/20
Productivity evaluation method and
design for manufacturability
JSAE Review 16 (1995) 375-381
Hiroshi Onitsuka, Kaoru Eguchi, Naoaki Miura, Hiroatsu Matsumura
Powertrain Prototype Engineering Department, Nissan Motor Co., Ltd., Kanagawa, Japan
Introduction



Nissan에서 미국 시장을 겨냥하여 개발한 VQ
engine에 적용된 방법론
높은 품질과 낮은 비용이 목적
엔진 조립 공정의 70%가 자동화
12/20
Productivity evaluation method



The degree of progress achieved in design for
manufacturability
The evaluation method provides an index of
how difficult a part would be to build, or the
poorness of its workability
Stabilize production quality and achieve low
cost level
13/20
Assembly productivity evaluation method

Standard time



Difficult operation time





Most fundamental work aspects of an element
부품을 줄이는 것으로 향상 가능
Additional time spent when the construction of a part
requires extra work
제거 가능한 다양한 방식의 작업이 존재
어떤 부품이 생산성 증가를 위하여 개선 가능한 지를 알려줌
Std time/dif oper time 중 어느 것이 효과적인 지 알려줌
제품 개발 초기 단계에 전체 line cycle time에 대한 추정
14/20
Maching productivity evaluation method



Cost of facilities와 cost of the tools로 평가
예를 들어, 가공해야 할 hole의 수가 많으면,
standard operation score가 높다.
Hole들이 가까이 있는 경우에는 multi-axis head를
사용할 수 없기 때문에 difficult operation score가
높다.
15/20
Design for global manufacturing and assembly
(DFGMA)
IIE Transactions 29 (1997) 585-597
G. Don Taylor
Dept. of IE, Bell Engineering Center, Univ. of Arkansas, USA
Introduction

Dowlatshahi(1992) reports



The design phase is responsible for only 5% of product
cost
But, it can determined 75% of the manufacturing cost and
80% of product quality performance
General DFX strategies are difficult to manage
in multi-facility, global settings
16/20
Mathematical formulation

Manufacturing cost
CM ijklm  CPijklm  CDijklm  CLijklm  CI ijklm
manufacturing= process + design + logistics + inventory
17/20
General DFGMA model

Objective function:
min :     CM Ijklm X Ijklm
j

k
l
m
 CS
   CT Y '
    CC
j
j
j
k
k
k
l
Ijk
l
manufacturing cost
Y
Ijkl Ijkl
set-up cost
Ijk
tooling cost
jkl
Z jkl
i : product I
j : process j
(1:automated, little flexible, 2: flexible)
k : site k
(Europe, Asia, North America)
l : period l (3 quarter period)
m : demand location
capital procurement cost
18/20
General DFGMA model
constraints

  X
j
k
l
Ijklm
  Dlm
l
I 1
 Cijkl ( X ijklm)  CIjkl ( X ijklm)  Ajkl
i 1
m
m
Ajk 0  1
Ajkl  Ajk,l 1  A' jkl (Z jkl )
X
X
m
l
Ijklm
Ijkl
 [M ](YIjkl )
Ajkl  0
X Ijklm  0, int
YIjkl  0,1, int
Y 'Ijk  0,1, int
Z jkl  0,1, int
 [M ](Y 'Ijk )
i : product I
j : process j
(1:automated, little flexible, 2: flexible)
k : site k
(Europe, Asia, North America)
l : period l (3 quarter period)
m : demand location
19/20
simulation
20/20