prod architecture
DESCRIPTION
product design theoryTRANSCRIPT
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Chapter 9: Product Architecture
Product Design and Development
Fourth Edition
by Karl T. Ulrich and Steven D. Eppinger
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Product Design and Development
Karl T. Ulrich and Steven D. Eppinger
2nd edition, Irwin McGraw-Hill, 2000.Chapter Table of Contents
1.Introduction
2.Development Processes and Organizations
3. Product Planning
4.Identifying Customer Needs
5.Product Specifications
6.Concept Generation
7.Concept Selection
8. Concept Testing
9.Product Architecture
10. Industrial Design
11.Design for Manufacturing
12.Prototyping
13.Product Development Economics
14.Managing Projects
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Planning
Product Development Process
Concept
Development
System-Level
Design
Detail
Design
Testing and
Refinement
Production
Ramp-Up
Product architecture is determined early in the development process.
Platform decision
Concept decision
Decomposition decision
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Product Architecture: Definition
The arrangement of functional elements into physical chunks which become the building blocks for the product or family of products.
Product
module
module
module
module
module
module
module
module
This is where we map the functions from our functional analysis/functional decomposition to physical design elements
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Aspects of Product Architecture
ModularityPoint of product differentiationImportance of Product Architecture
Decided early and drives designImpacts manufacturing costImpacts product evolutionImpacts organization structure of design teamsWe are looking at these topics early because they matter to the early stage of design. We also dont want to lock ourselves out of the possibility of later product enhancements (adding a sunroof, adding a supercharger, etc)
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Modular Design Displays the Following Properties:
Each physical chunk implements one or a few functional elements in their entiretyThe interactions between chunks are well defined (i.e. the interfaces are well defined)*
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Integral Product Architectures
Functional elements are implemented by multiple chunks, or a chunk may implement many functions.Interactions between chunks are poorly defined.Integral architecture generally increases performance and reduces costs for any specific product model. -
Modular or Integral?
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Examples
Video GamesModular: gaming systems (e.g. GameCube)Integrated: stand-alone arcade gamesPower SuppliesModular: power bricksIntegrated: on-board power converter*
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Trailer Example:
Modular Architecturebox
hitch
fairing
bed
springs
wheels
protect cargo
from weather
connect to
vehicleminimize
air dragsupport
cargo loads
suspend
trailer structuretransfer loads
to roadOne function one design element
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Trailer Example:
Integral Architectureupper half
lower half
nose piece
cargo hanging
strapsspring slot
covers
wheels
protect cargo
from weather
connect to
vehicleminimize
air dragsupport
cargo loads
suspend
trailer structuretransfer loads
to roadFunctions may map to several design elements or several functions may map to a single design element
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Integral vs. Modular
Integral
Higher system performanceTightly coupled design teamsHard to changeModular
Reduced performanceDecoupled design teamsRequires clear definition of interfacesIncreased flexibilityAccommodates made-to-order productsA single straight screwdriver is often more satisfying than an interchangeable tip screwdriver wit the same blade
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Integral vs. Modular
Integral
Higher system performanceLower system cost (in large volume)Tightly coupled design teamsExpensive ToolingHard to changeModular
ChangeabilityDecoupled design teamsReduced performanceRequires flexible manufacturingCheaper at low volumeshttp://web.mit.edu/course/2/2.996/www/lecture5/sld038.htm
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What is this?
Note that this is a nearly pure modular design in that each function maps to a single design element
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Nail Clippers?
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Modular or Integral Architecture?
Motorola StarTAC
Cellular Phone
Rollerblade
In-Line Skates
Ford
Explorer
Apple
iBook
You will notice that all designs have aspects of both, but most electronics are assemblies of modules like keyboard, hard drive, screen that can be swapped out with more or less ease. Laptops tend to be more integral while destops tend to be more modular. Apple tends toward more modular vversions of dektops in which some of their designs have had the monitor and computer in a single case.
Automobiles have traditionally been more integral than modular, though frequently replaced items like windsield wipers, wheels and batteries tend to have a little more flexible interfaces.
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Types of Modularity
Slot-Modular Architecture unique interfaces for attachment to a base element (e.g. pacemaker leads)Bus-Modular Architecturecommon interfaces for attachment to a base element (e.g. USB connectors on a computer)Sectional-Modular ArchitectureCommon interfaces between elements without a base element (e.g. legos & piping)*
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Bus?
Slot?
Sectional?
The specific ports for printer, keyboard and mouse are examples of SLOT modular
While the USB can handle printer, keyboard and mouse with a single port type, making it an example of BUS modular
So what is sectional?
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Sectional is a collection of parts that can fit together in multiple ways. Interface design is very important here as well. (Note that a welded pressure vessel (like an airplane fuselage is a collection of parts )modules) with welds as the interface. A filament wound pressure vessel is an integral design for the same function.
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Choosing the Product Architecture
Architecture decisions relate to product planning and concept development decisions:
Product Change (copier toner, camera lenses)Product Variety (computers, automobiles) Standardization (motors, bearings, fasteners)Performance (racing bikes, fighter planes)Manufacturing Cost (disk drives, razors)Project Management (team capacity, skills)System Engineering (decomposition, integration) -
The concepts of integral and modular apply at several levels:
systemsub-systemcomponent -
Product Architecture = Decomposition + Interactions
Interactions within chunksInteractions across chunks -
Product Architecture Example:
Hewlett-Packard DeskJet Printer -
Establishing the Architecture
To establish a modular architecture, create a schematic of the product, and cluster the elements of the schematic to achieve the types of product variety desired.
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DeskJet Printer Schematic
Flow of forces or energy
Flow of material
Flow of signals or data
Store
OutputStore
Blank
PaperEnclose
PrinterProvide
Structural
Support
Print
Cartridge
Position
Cartridge
In X-Axis
Position
Paper
In Y-Axis
Supply
DC
Power
Pick
Paper
Control
Printer
Command
Printer
Connect
to
Host
Communicate
with
Host
Display
Status
Accept
User
Inputs
Functional
or Physical
Elements
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Cluster Elements into Chunks
Store
OutputStore
Blank
PaperEnclose
PrinterProvide
Structural
Support
Print
Cartridge
Position
Cartridge
In X-Axis
Position
Paper
In Y-Axis
Supply
DC
Power
Pick
Paper
Control
Printer
Command
Printer
Connect
to
Host
Communicate
with
Host
Display
Status
Accept
User
Inputs
Paper Tray
Print
MechanismLogic Board
Chassis
Enclosure
User Interface Board
Host Driver
Software
Power Cord
and Brick
Functional
or Physical
Elements
Chunks
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Geometric Layout
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Incidental Interactions
Enclosure
Paper Tray
Chassis
Print
Mechanism
User Interface
Board
Logic
Board
Power Cord
and Brick
Host Driver
Software
Styling
Vibration
Thermal Distortion
Thermal Distortion
RF Interference
RF Shielding
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Additional Advantage to Modular Design:
Modular design to allow components to be removed, upgraded or replaced Eliminating glues and adhesives, for example, by using snap-in features Marking plastic parts weighing more than 25g according t ISO 11469 international standards, to speed up materials identification during recycling Reducing the number and types of materials used Using single plastic polymers Using molded-in colors and finishes instead of paint, coatings or plating Relying on modular designs for ease of disassembly of dissimilar recyclable materials
HP products are designed to be recycled. Recycling design features include:http://www.hp.com/hpinfo/globalcitizenship/environment/productdesign/endoflife.html
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Planning a Modular Product Line:
Commonality TableDifferentiation versus Commonality
Trade off product variety and production complexity
Chunks
Number of TypesFamilyStudent
SOHO (small office, home office)
Print cartridge
2
Manet Cartridge
Picasso Cartridge
Picasso Cartridge
Print Mechanism
2
"Aurora" Series
Narrow "Aurora" series
"Aurora" series
Paper tray
2
Front-in Front-out
Front-in Front-out
Tall Front-in Front-out
Logic board
2
Next gen board with parallel port
Next gen board
Next gen board
Enclosure
3
Home style
Youth style
Soft office style
Driver software
5
Version A-PCVersion A-Mac
Version B-PCVersion B-Mac
Version C
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Fundamental Decisions
Integral vs. modular architecture?What type of modularity?How to assign functions to chunks?How to assign chunks to teams?Which chunks to outsource? -
System Team Assignment
Based on Product ArchitectureFrom Innovation at the Speed of Information, S. Eppinger, HBR, January 2001.
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Practical Concerns
Planning is essential to achieve the desired variety and product change capability.Coordination is difficult, particularly across teams, companies, or great distances.Special attention must be paid to handle complex interactions between chunks (system engineering methods). -
Product Architecture: Conclusions
Architecture choices define the sub-systems and modules of the product platform or family.Architecture determines:ease of production varietyfeasibility of customer modificationsystem-level production costsKey Concepts:modular vs. integral architectureclustering into chunksplanning product families -
Power Bricks are annoying to most consumers.
Why are they viewed as a good example of modular design?
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Product Structure
Make to order (Dell Computers)Make to stock (Roaster Pans)Delayed Differentiation (Washing Machines) -
Design Conflict:
Integral DesignFocused mission/manufacturingExample conventional screwdriver Modular DesignFlexible mission/manufacturingExample bit holder and driver bits
Low Cost vs. Large Variety -
Point of Product Differentiation
The point in the manufacturing process where a product can only be made into a specific stock keeping unit (SKU)
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Delayed Point of Product Differentiation
The point in the manufacturing process where an item is limited to use for a single specific product is called the Point of Product DifferentiationDelaying the point of product differentiation is called Late Point Product Differentiation*
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Delayed differentiation or Postponement is a concept in supply chain management where the manufacturing process starts by making a generic or family product that is later differentiated into a specific end-product. This is a widely used method, especially in industries with high demand uncertainty, and can be effectively used to address the final demand even if forecasts cannot be improved.
An example would be Benetton and their knitted sweaters that are intially all white, and then dyed into different colored only when the seasons customer color preference/demand is know. It is usually necessary to redesign the products specifically for delayed differentiation, and resequence to modify the order of product manufacturing steps.
From Wikipedia
back
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Advantages of Late Point Product Differentiation
Reduced inventoriesMore easily respond to demand variation*
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Late Point Differentiation Examples
Paint where pigment is added at the storeBenetton sweatersHP printers*
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http://web.mit.edu/course/2/2.996/www/lecture5/sld038.htm
Modular Design allows for Late Point Differentiation
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http://web.mit.edu/course/2/2.996/www/lecture5/sld038.htm
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http://web.mit.edu/course/2/2.996/www/lecture5/sld038.htm
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Late Point Differentiation Principles
The differentiating elements of the product must be concentrated in one or a few chunksThe product and production process must be designed so that the differentiating chunk(s) can be added to the product near the end of the supply chain.*
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Platform Planning
The process of deciding what should be shared across products and what should be unique across products?
For example:
How many driveshafts should you have for a Ford F150?Note that the current ford F150 has 5 different wheelbases (different cab length and different bed length)
There are also two different engines. Should there be different driveshaft for each engine? Advantages, disadvantages.
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Platform Planning
Attempts to resolve the tension betweenDifferentiating the product for various customers
Taking advantage of the economic benefits of using common components
Product architecture will determine what trade-offs are available if no good options are available, see if the options can be improved by changing the product architecture*
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In-class exercise
Your company manufactures and sells spinal fixation devices. Assume that the design concept is to secure a rigid body (e.g. a metallic plate) to adjacent vertebrae so that the unstable region is immobilized.Consider how product architecture could impact your design. Please note that your product needs to serve a population where spines come in a variety of sizes.What would be the embodiment of this design concept for a modular design?What would be the embodiment of this design concept for an integrated design?*
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In-Class Exercise 1:
Your company manufactures and sells spinal fixation devices.
Assume that the design concept is to secure a rigid body (e.g. a metallic device) to adjacent vertebrae so that the unstable region is immobilized.
Consider how product structure could impact your design. Please note that your product needs to serve a population where spines come in a variety of sizes.
What would be the embodiment of this design concept for a modular design?
What would be the embodiment of this design concept for an integrated design?
How do these embodiments impact late point identification.?
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Chunks
Number of
Types
Family Student SOHO
(small office, home office)
Print cartridge 2 Manet Cartridge Picasso Cartridge Picasso Cartridge
Print Mechanism 2 "Aurora" Series Narrow "Aurora" series "Aurora" series
Paper tray 2 Front-in Front-out Front-in Front-out Tall Front-in Front-out
Logic board 2 Next gen board
with parallel port
Next gen board Next gen board
Enclosure 3 Home style Youth style Soft office style
Driver software 5 Version A-PC
Version A-Mac
Version B-PC
Version B-Mac
Version C
F
G
E
D
I
A
C
B1
K1
J
P
N
Q
R
B2
K2
O
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M
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U
V
Crankshaft
F
F
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Flywheel
G
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G
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Connecting Rods
E
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E
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Pistons
D
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D
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Lubrication
I
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I
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Engine Block
A
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A
l
l
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Camshaft/Valve Train
C
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C
l
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l
Cylinder Heads
B1
l
l
l
l
l
B1
l
l
l
l
l
l
Intake Manifold
K1
l
l
l
l
K1
l
l
l
l
l
Water Pump/Cooling
J
l
l
l
l
l
l
J
l
l
l
l
l
l
l
l
l
Fuel System
P
l
P
l
l
l
l
l
l
l
l
l
l
Air Cleaner
N
l
N
l
l
l
l
l
l
Throttle Body
Q
l
l
l
Q
l
l
l
l
l
l
l
l
l
EVAP
R
l
l
R
l
l
l
Cylinder Heads
B2
l
l
l
B2
l
l
l
l
l
l
l
l
Intake Manifold
K2
l
l
l
l
l
l
K2
l
l
l
l
l
l
l
A.I.R.
O
l
l
l
l
l
l
O
l
l
l
l
l
l
Exhaust
L
l
l
l
l
l
l
l
l
L
l
l
l
l
l
l
E.G.R.
M
l
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M
l
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Accessory Drive
H
l
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H
l
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l
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Ignition
S
l
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l
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l
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l
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S
l
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E.C.M.
T
l
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T
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Electrical System
U
l
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l
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l
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U
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Engine Assembly
V
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V
Frequency of PDT Interactions
l
Daily
l
Weekly
l
Monthly
Team 1
Team 2
Team 3
Team 4
Integration
Team