A new approach to product structures for product families

1
A new approach to product structures for product
families
Pierre De Lit May 18, 2000
2
What will we talk about ?

• Introduction
• Decomposition into functional entities
• Generic and variant constituents
• Product structure
• Design issues
• Conclusions

3
What will we talk about ?

• Introduction
• Decomposition into functional entities
• Generic and variant constituents
• Product structure
• Design issues
• Conclusions

4
The aim is to design mixed models hybrid assembly
lines

• Multivariant
• Different kinds of stations
• Manual
• Dedicated/Robotic

5
What is a product family?

• Group of products
• Specific design concept or derived from a
  standard/parent product
• assembled on so-called multi-product assembly
  lines
• Components which are common and other ones which
  are optional

6
Trends in product families structuring

• Customers point of view
• Parameters to select the desired variant
• Manufacturers point of view
• GBOM
• Concerned components and features
• Assemblers point of view
• (GBOM)
• Concerned components and features
• Links and features

7
What will we talk about ?

• Introduction
• Decomposition into functional entities
• Generic and variant constituents
• Product structure
• Design issues
• Conclusions

8
A first problem complexity explosion
Body 3 variants
Cover 3 variants
Diodes 3 variants
Alternator 27 variants
A global multi-variant approach on 27 variants
is difficult
9
A solution functional entities (FEns)

• the product decomposition eases the analysis
  (little number of variants)
• the product is an assembly of FEns
• FEns are chosen by the user

10
Product variants are described as a combination
of FEn variants
FEns variants
Alternator
Body
Diodes
Cover
1



2



11
What will we talk about ?

• Introduction
• Decomposition into functional entities
• Generic and variant constituents
• Product structure
• Design issues
• Conclusions

12
Each component is presented by a fictitious
generic one

• the definition is based on functional equivalence

a
a
A
a
B
b
13
Components typology

• Unvarying components
• only one variant
• in all variants of a CFEn
• Pseudo-varying components
• in all variants of a CFEn
• variants do not interfere with the production
  process
• Varying components
• in all variants of a CFEn
• variants interfere with the production process
• Optional components

14
Links become generic ones

• Unvarying links
• Varying links

15
Generic elements are used to design a unique
assembly line

• Each constituent is represented by a fictitious
  generic element
• The links between the components are generic
  links
• Systematise the use of a single equipment for a
  generic element use
• Maximise similarities between equipment for a FEn

16
What will we talk about ?

• Introduction
• Decomposition into functional entities
• Generic and variant constituents
• Product structure
• Design issues
• Conclusions

17
The family is studied as a whole
18
FEn typology

• Common FEn (CFEn)
• In all products of the family
• Specific FEn (SFEn)
• In some products of the family
• Structure index

19
FEns introduce modularity in the analysis

• The product is analysed FEn by FEn
• Two levels
• A first level related to the assembly of the FEns
  to each other
• A second level related to the assembly of the FEn
  itself

20
Preliminary design phase

• Product described as an assembly of FEns
• Only conceptual links exist between the FEns

21
As design advances some FEns are described
Body
Palier avant
Stator
Roulement
Passe-fils
Palier arrière
Voile
Rotor
Pâte conductrice
Roulement
Poulie
Cover
Diodes
Box
22
Advanced design complete description of the
product
Body
Palier avant
Stator
Roulement
Passe-fils
Palier arrière
Rotor
Voile
Pâte conductrice
Roulement
Poulie
Diodes
Régulateur
Pont diodes
Pâte isolante
Cache-balais
Support
Box
Prolongateur
Cover
23
What will we talk about ?

• Introduction
• Decomposition into functional entities
• Generic and variant constituents
• Product structure
• Design issues
• Conclusions

24
Design implications product structure

• Product should be devised as an assembly of FEns
• Istruc index should be high
• Links between FEns should be single ones
• Standardise interfaces between FEns
• Apply common DFA rules (early design)

25
Design implications components

• Try to maximise unvarying components
• Pseudo-varying ? unvarying components
• Varying components
• standard interfaces
• standard gripping surfaces
• Avoid multiplication of resources

26
What will we talk about ?

• Introduction
• Decomposition into functional entities
• Generic and variant constituents
• Product structure
• Design issues
• Conclusions

27
Let us conclude

• Product is an assembly of FEns
• with less variants than the family
• easier to study and design
• FEns uncouple the analysis
• FEns allow to deal with partial information on
  the product
• Same set of resources should be used for a FEn