Product Architecture and Modularity

1. Product Architecture and Modularity Systems Engineering MG587 Karl T. Ulrich and Steven D. Eppinger3rd Edition, Irwin McGraw-Hill, 2004.

2. Product Architecture: Definition The arrangement of functional elements into physical chunks which become the building blocks for the product or family of products. module module Product module module module module module module

3. Other terms for “Chunks” • A ‘Chunk’ is made up of a collection of components that carry out various functions/sub-functions of the product. • Other terms for “Chunks” or elements that make up a chunk • Subsystem • Cluster • Module • Building blocks • ‘Interfaces’ connect these chunks together.

4. Architecture • The Architecture of a product is the scheme by which the functional elements of the product are arranged into physical chunks and by which the chunks interact.

5. Product Development Process Concept Development System-Level Design Detail Design Testing and Refinement Production Ramp-Up Planning Platform decision Concept decision Decomposition decision Product architecture is determined early in the development process. This is not a linear, sequential process.

6. Architecture Decisions

7. 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)

8. How Does Architecture Happen? • Ulrich and Eppinger – ‘Chunks’ approach. • MIT – Design Structure Matrix. • Buede – Decomposition, • Physical mirrors Functional structures. • Dominant Flow Heuristics- R. B. Stone

9. Architectures: Challenge X

10. Modular or Integral Architecture? Apple iBook Motorola StarTAC Cellular Phone Rollerblade In-Line Skates Ford Explorer

11. Modular Product Architectures • Chunks implement one or a few functions entirely. • Interactions between chunks are well defined. • Modular architecture has advantages in simplicity and reusability for a product family or platform. Swiss Army Knife Sony Walkman

12. Trailer Example:Modular Architecture box protect cargo from weather hitch connect to vehicle fairing minimizeair drag bed support cargo loads springs suspendtrailer structure wheels transfer loadsto road

13. Trailer Example:Integral Architecture upper half protect cargo from weather lower half connect to vehicle nose piece minimizeair drag cargo hangingstraps support cargo loads spring slot covers suspendtrailer structure wheels transfer loadsto road

14. 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. Compact Camera

15. Ford Taurus Integrated Control Panel

16. Discussion Question • Is one type of product architecture (modular vs. integral) better than the other? • Performance • Platforms • Serviceability • Interfaces • Cost to manufacture • Cost to develop

17. Steps to Establish the Product Architecture – Ulrich and Eppinger • Create a functional model or schematic of the product. • Cluster the elements on the schematic. • Make Geometric Layouts to achieve the types of product variety. • Identify Interactions • Fundamental (must interact) • Incidental

18. Physical and/or Functional Connect Elements Which Have Fundamental Interactions Show “Motion” & “Flow” Step 1: Functional or Schematic Diagram Example: Rapid Prototyping Machine using laser sintering

19. Reasons to Cluster close geometric relationship function sharing modular desire to outsource Step 2: Cluster Elements into Chunks Laser Table Control Cabinet Atmospheric Control Unit Powder Engine

20. Step 3: Produce Geometric Layout Note: If you can’t make a geometrical layout then go back and redefine chunks and identify interactions

21. Step 4: Identify Interactions • Forces consideration of geometric interfaces to accommodate flows • Illustrates possible problems caused by interactions • Fundamental • Lines on the schematic that connect chunks • Usually a well understood property • Incidental • Usually not shown on schematic • Higher order effects/interferences

22. Product Architecture Example:Hewlett-Packard DeskJet Printer Part of a portfolio architecture and is composed of parts within a product architecture

23. EnclosePrinter Print Cartridge Provide Structural Support Accept User Inputs Display Status Position Cartridge In X-Axis StoreOutput Position Paper In Y-Axis Control Printer Supply DC Power StoreBlankPaper “Pick” Paper Communicate with Host Command Printer Functional or Physical Elements Flow of forces or energy Flow of material Flow of signals or data Connect to Host DeskJet Printer Schematic

24. Enclosure EnclosePrinter Print Cartridge User Interface Board Provide Structural Support Accept User Inputs Display Status Position Cartridge In X-Axis Chassis StoreOutput Position Paper In Y-Axis Control Printer Power Cord and “Brick” Supply DC Power StoreBlankPaper “Pick” Paper PrintMechanism Paper Tray Communicate with Host Command Printer Host Driver Software Functional or Physical Elements Chunks Connect to Host Logic Board Cluster Elements into Chunks

25. Geometric Layout

26. Enclosure User Interface Board Styling Thermal Distortion Vibration Paper Tray Print Mechanism Logic Board Host Driver Software RF Interference Thermal Distortion RF Shielding Chassis Power Cord and “Brick” Incidental Interactions

27. Dominant Flow Heuristics • Heuristic 1: “The set of sub-functions through which a flow passes, from entry or initiation of the flow in the system to exit from the system or conversion of the flow within the system, define a module.” • Energy • Material • Information Function System The Wok Example

28. Generic Dominant Flow Illustration Material Interface Energy Interaction

29. Dominant Flow Example • Fragment of the iced tea brewer FM

30. Branching Flow • Heuristic 2: “Parallel function chains associated with a flow that branches constitute modules. Each of the modules interfaces with the remainder of the product through the flow at the branch.”

31. Generic Branching Flow Illustration Branch Module/Chunk #1 Material Interface Module/Chunk #2

32. Branching Flow Example • Fragment of the iced tea brewer FM

33. Conversion-Transmission Modules • Heuristic 3: A conversion sub-function or a conversion-transmission pair or proper chain of sub-functions constitutes a module.

34. Conversion-Transmission Example • Fragment of the iced tea brewer FM

35. The Design Structure Matrix (DSM): An Information Exchange Method Interpretation: • Task D requires information from tasks E, F, and L. • Task B transfers information to tasks C, F, G, J, and K. Note: • Information flows are easier to capture than work flows. • Inputs are easier to capture than outputs. Donald V. Steward, Aug. IEEE Trans. on Eng. Mgmt. 1981

36. DSM (Partitioned, or Sequenced) Note: Manipulate the matrix to emphasize features of the process flow. Sequential, parallel and coupled tasks can be identified. Clustering Algorithms

37. System Team AssignmentBased on Product Architecture From “Innovation at the Speed of Information”, S. Eppinger, HBR, January 2001.

38. Modularity • Modularity is a product development strategy in which interfaces shared among components in a given product architecture become specified and standardized to allow for greater substitutability of components across product families.

39. Types of Modular Designs • Slot • Bus • Sectional • All retain a 1-to-1 mapping of functional to physical elements

40. Modular Integral Modular vs. Integral

41. Example of Modularity K. Ulrich, “The Role of Product Architecture in the Manufacturing Firm” Research Policy, 24, 419-440 (1995)

42. Example of Modularity K. Ulrich, “The Role of Product Architecture in the Manufacturing Firm” Research Policy, 24, 419-440 (1995)

43. Example of Modularity K. Ulrich, “The Role of Product Architecture in the Manufacturing Firm” Research Policy, 24, 419-440 (1995)

44. Sony Walkman

45. Product Model Lifetime F r a c t i o n S u r v i v i n g S o n y A I W A A v e r a g e L i f e 1 . 0 T o s h i b a S o n y O t h e r s 1 . 9 7 y r 1 . 1 8 y r P a n a s o n i c 0 . 8 About 200 versions of the Sony Walkman from four platforms! 0 . 6 0 . 4 0 . 2 0 0 1 2 3 4 5 S u r v i v a l T i m e ( y e a r s ) From Sanderson and Uzumeri, The Innovation Imperative, Irwin 1997.

46. Platforms and Modularity

47. Some Modularity Benefits • Production of a great variety of end products from a limited number of building blocks • Platform strategy permitting many product variants based on a stable architecture • Facilitate changes to current and future products • Simplifies parallel testing • Serviceability • Allows for parallel development of design teams • Allows for outsourcing

48. Some Limitations to Modularity • Cannot discriminate look alike products • Increases the risk of competitors copying designs • Generally increases unit cost ( more components), volume (size) or weight of the product • More interfaces are less reliable (why??) • Depends on the capabilities of designers

49. Impact of Modularity Decisions on Later Design Processes

50. Product Architecture Example:Hewlett-Packard DeskJet Printer