1. PENN S TATE © T. W. S IMPSON PENN S TATE Timothy W. Simpson Professor of Mechanical & Industrial Engineering and Engineering Design The Pennsylvania State University University Park, PA 16802 phone: (814) 863-7136 email: tws8@psu.edu http://www.mne.psu.edu/simpson/courses/me546 Modularity and Product Architecting ME 546 - Designing Product Families - IE 546 © T. W. S IMPSON

2. PENN S TATE © T. W. S IMPSON Recall: Pine’s Five Steps to Mass Customization Degree of Market Turbulence Degree of Organizational Turbulence Customize Services Embed Customizability Create Point-of-Delivery Customization Provide Quick Response Modularize 1 2 3 4 5 Sources: Pine, B. J., II, 1993, "Mass Customizing Products and Services," Planning Review, Vol. 22, No. 4, pp. 6(8). Pine, B. J., II, 1993, Mass Customization: The New Frontier in Business Competition, Harvard Business School Press, Boston, MA.

3. PENN S TATE © T. W. S IMPSON Overview of Today’s Lecture MODULARITY IS THE KEY enabler for successful product family design and product platforms. What is product architecture? What types exist? What is modular design? What is its role in product family and product platform design? What is an interface? What is a module? What are the different types of modularity? What is a function? What is a function structure?

4. PENN S TATE © T. W. S IMPSON ContemporaryBeach Source - www.coolhouseplans.com Architecture

5. PENN S TATE © T. W. S IMPSON System Boundary Slide adapted from O. de Weck & T. Simpson, MIT ESD 39s System Architecture

6. PENN S TATE © T. W. S IMPSON Architecture: Definition Architecture  The embodiment of concept, and the allocation of physical/informational function (process) to elements of form (objects) and definition of the structural interfaces among the objects Consists of:  Function  Related by Concept  To Form Form Function Concept Slide adapted from O. de Weck & T. Simpson, MIT ESD 39s

7. PENN S TATE © T. W. S IMPSON Function: provide for 1) meeting place 2) visible main speaker 3) processions Concept: church (Basilica) Function: provide for 1) meeting place 2) visible large “cast” Concept:amphitheater Function: provide for1) meeting place 2) each participant visible to others Concept: meeting room Form Often Follows Function Form raised Function-Concept-Form Slide adapted from O. de Weck & T. Simpson, MIT ESD 39s

8. PENN S TATE © T. W. S IMPSON Product Architecture Product architecture is:  “the scheme by which the function of a product is allocated to physical components” (Ulrich, 1995) Purpose of product architecture is:  “to define the basic physical building blocks of the product in terms of what they do and what their interfaces are to the rest of the device” (Ulrich & Eppinger, 2000) More formally, a product architecture is (Ulrich, 1995):  the arrangement of functional elements  the mapping of functional elements to physical components  the specification of the interfaces among physical components Sources: Ulrich, K., 1995, "The Role of Product Architecture in the Manufacturing Firm," Research Policy, Vol. 24(3), pp. 419-440. Ulrich, K. T. and Eppinger, S. D., 2000, Product Design and Development (2nd Ed.), McGraw-Hill, NY, NY.

9. PENN S TATE © T. W. S IMPSON Example: Coffee Maker Mix Coffee and Water Heat Coffee Heat Water Store Water Electricity Water Ground Coffee Brew Coffee Overall Function Supporting Sub-Functions Auxiliary Functions Shut-off Heater Coffee Beans Grind Beans Store Grounds Store Coffee

10. PENN S TATE © T. W. S IMPSON How to Create a Function Structure Source: Pahl, G. and Beitz, W., 1996, Engineering Design: A Systematic Approach (2nd Rev. Ed.), Springer-Verlag, New York. 1.Formulate the overall product function 2.Split up overall function into sub-functions 3.Determine simplified functions structure 4.Identify material, energy, and information/signal flows 5.Add secondary/auxiliary functions and flows

11. PENN S TATE © T. W. S IMPSON Morphological Matrix Search for solution principles to fulfill sub-functions  Identify as many solutions for each sub-function and auxiliary functions as possible Combine solutions to embody physical concepts  Use morphological matrix to identify combinations of solutions  Each combination of solutions will fulfill overall function Use expertise and heuristics to eliminate infeasible solution combinations Morphological Matrix [PB96]

12. PENN S TATE © T. W. S IMPSON Morphological Matrix for Coffee Maker Heat Coffee Heat Water Store Water Store Grounds Mix Coffee and Water Store Coffee Brew Coffee S11S12  S1jS1m  Si1Si2  SijSim  Sn1Sn2  SnjSnm           FilterOsmosisDissolveIonize  Stir

13. PENN S TATE © T. W. S IMPSON Modular and Integral Architectures Defined After we identify solutions for each function, we can combine them to identify modules in the architecture Modularity is defined as (Ulrich and Tung, 1991): 1.there is a one-to-one correspondence between functional elements and physical structures...AND... 2.unintended interactions between modules are minimized (i.e., component interfaces are de-coupled). The opposite of modular is referred to as integral  A modular architecture (ideally) has:  One physical component/function; de-coupled interfaces while an integral architecture has:  Coupled interfaces; many functions/physical component

14. PENN S TATE © T. W. S IMPSON Coupled vs. Uncoupled Designs Axiom: Maintain the interdependence of functional requirements (N. P. Suh, Principles of Design, 1990) Reference: Billy Fredriksson, Holistic systems engineering in product development, Griffin, Saab-Scania, Nov. 1994/95 Coupled Design Uncoupled Design Slide adapted from O. de Weck & T. Simpson, MIT ESD 39s

15. PENN S TATE © T. W. S IMPSON Types of Modularity: Slot In a slot architecture, each module has a different interface with the overall system. Why different interfaces?  So that various components cannot be interchanged Examples:  SCSI, Ethernet, and parallel ports on laptop 

16. PENN S TATE © T. W. S IMPSON Types of Modularity: Bus In a bus architecture, there is a common bus to which modules connect via the same interface. What are the advantages of this type of modularity? Examples:  Modem and Internet cards on laptop; CD and disk drive 

17. PENN S TATE © T. W. S IMPSON Types of Modularity: Sectional In a sectional architecture, all interfaces are the same type but there is no single element to which modules attach. What are advantages and disadvantages of a sectional approach? Examples:  Legos  Using a sectional architecture, the assembly is built up by connecting the modules to each other via identical interfaces.

18. PENN S TATE © T. W. S IMPSON Sectional Modularity at Nippondenso Nippondenso can make 288 different panel meters from variations of 8 modules (17 different parts) © T. W. S IMPSON, 2001

19. PENN S TATE © T. W. S IMPSON Products, Modules, and Attributes Product 1 Product 2 ProductsModules Module Attributes Different products A1 B1 C1 D1 A1 B2 C2 Types of Modules: Common A1 Variant C1,C2 Unique B1, B2, D1 Types of Modules: Common A1 Variant C1,C2 Unique B1, B2, D1

20. PENN S TATE © T. W. S IMPSON Example: B&D Versapack® Toolkit Unique Common Variant

21. PENN S TATE © T. W. S IMPSON Creating a Module-Based Product Family 1.Decompose products into their representative functions 2.Develop modules with one-to-one (or many-to-one) correspondence with functions 3.Group common functional modules into a common product platform Common Functions Specific Function 1 Specific Function 2 Specific Function k Derivative Product 1 Derivative Product 2 Derivative Product k 4.Standardize interfaces to facilitate addition, removal, and substitution of modules Product Family { Product Platform }

22. PENN S TATE © T. W. S IMPSON Example: Braun Family of Coffee Makers KF130 Basic Model KF180 Auto Shut- off, Clock KF185 Adjustable Heater KF190 Frothing Attachment KF170 Thermos Karafe KF145 Water Filter Common Function Brew Coffee Electricity Water Ground Coffee Mix Coffee and Water Heat Coffee Store Water Store Grounds Store Coffee Heat Water

23. PENN S TATE © T. W. S IMPSON Developing Modular Architectures What are some rules of thumb you, as an engineer, might follow to develop a modular product architecture? 

24. PENN S TATE © T. W. S IMPSON Some Heuristics for Module Development Stone, et al. (1998) developed a set of three heuristics to identify product modules from a function structure:  Dominant Flow: – examines flows through a function structure, following flows until they either exit from the system or are transformed – the sub-functions through which these flows are traced define a module  Branching Flows: – examines flows that branch into or converge from parallel function chains – each branch of a flow can become a module; modules interface at point where flow branches or converges  Conversion-Transmission: – examines flows that are converted from one type to another – develop a module which converts an energy or material flow into another form and then transmits it

25. PENN S TATE © T. W. S IMPSON Some Heuristics for Module Development Zamirowski and Otto (1999) define two heuristics to aid in module identification within a product family:  Shared Functions: – functional groups which share similar flows and functions and appear multiple times within a product family should be grouped into a single module – this module can then be reused across the product family  Unique Functions: – identify functions that are unique to a single product or subset of products – group functions into modules to facilitate product variety

26. PENN S TATE © T. W. S IMPSON Advantages of Modular Architectures Facilitates product change and product variety  modules can easily be upgraded, degraded, and added-on  modules can easily be reused or replaced Modular products can be quickly reconfigured to meet changing market requirements Improves economies of scale through component and module sharing across products (economies of scope)

27. PENN S TATE © T. W. S IMPSON Disadvantages of Modular Architectures Easier to reverse engineer Modular products tend to sub-optimal Assembly costs are slightly higher

28. PENN S TATE © T. W. S IMPSON Advantages of Integral Architectures Facilitates the optimization of “holistic performance characteristics and those that are driven by the size, shape, and mass of a product” [UE00] Minimizes redundancy through function sharing Minimizes number of parts which much be assembled

29. PENN S TATE © T. W. S IMPSON Disadvantages of Integral Architectures Difficult to upgrade and reconfigure Adjusting or “fine-tuning” a single function can be more complex and difficult Components and modules cannot be easily replaced if worn or broken

30. PENN S TATE © T. W. S IMPSON Modular vs. Integral Architectures As product functionality overshoots customer needs, modular architectures become more competitive Time Performance Sustaining Technology Integral Architectures Modular Architectures Disruptive Technology Adapted from: C. Christensen and M. Verlinden, 2002, "Disruption, Disintegration, and the Dissipation of Differentiability," Industrial and Corporate Change, vol. 11(5), pp. 955-993. Customer Needs and Expectations Compete through superior functionality Compete through speed, customization, and convenience High Med Low